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  • 251.
    Fahlvik, Adam
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    3D-skrivare för prototyptillverkning i plast 20162016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis project has been to investigate which new 3D printing equipment

    would be of greatest use for the company Dalelven Produkutveckling AB.

    Through interviews with the company's project leaders the company's needs for new equipment has been identified.

    Information about 3D printers, processingmethods and perihpal equipment has been gathered and sorted. With the support of theories from Quality Function Deployment 3D printers have been evaluated and sorted in categories in accordance with the company's needs.

    Dalelven need to be able to create prototypes in several kinds of plastic. In comparison between the most interesting 3D printers Stratasys polyjet printers from their Objet Connex series got the highest score (exluding HP's “Multi Jet Fusion” printers that not yet are for sale).

    In a comparison between 3D printers that print with thermoplastics it was observed that a couple of relatively unknown companies is producing 3D printers with in some categories better specifications than the established companies alternatives.

  • 252.
    Fakih, Abdullah
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Undersökning av rullfriktionsplanetväxel: Undersökning i FEM och framtagning av dimensioneringsverktyg2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The work is about improvement analysis of a planetary gear. The gear is affected by the friction between the planetary roller and the sleeve. This means that there are no cogs on the wheels, but the rotating parts of the planetary gear are completely round. The friction occurs after the shrinkage of a sleeve on three planetary rollers that is seated in a planetary holder. A company in Smedjebacken uses the planetary gear in their electric hybrid system and during the test run, the planetary gear has failed. The company has carried out an investigation into the cause of the accident and concluded that the sleeve becomes oval after the shrinkage which causes imbalance of the future gear at high speeds. I was commissioned to investigate how the sleeve is affected after the shrinkage and the production of a dimensioning tool that is based on Excel for an improvement proposal for the sleeve.

    The approaches that have been used to fulfill purpose are the gathering of information consisting of interviews and information on the parts of the planetary gear. Furthermore, literature research was carried out to obtain a comprehensive picture of the problem and own studies of the existing sleeve.

    The method has been divided into two parts. Firstly, the examination of the sleeve in the finite element method (FEM) and secondly determine how the structure of the dimensioning tool should be designed. The design tool structure consists of three sheets in Excel program. The first sheet introduces and explains how it works. The second sheet is static calculations that show how the forces act in the sleeve depending on the angle. The last sheet contains Calculations that are based on Hertz's surface pressure. Future work can be the improvement of dimensioning tools and a wider investigation into the cause of the failure of the planetary gear in the hybrid system.

  • 253.
    Fallqvist, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Microstructural, Mechanical and Tribological Characterisation of CVD and PVD Coatings for Metal Cutting Applications2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The present thesis focuses on characterisation of microstructure and the resulting mechanical and tribological properties of CVD and PVD coatings used in metal cutting applications. These thin and hard coatings are designed to improve the tribological performance of cutting tools which in metal cutting operations may result in improved cutting performance, lower energy consumption, lower production costs and lower impact on the environment.  In order to increase the understanding of the tribological behaviour of the coating systems a number of friction and wear tests have been performed and evaluated by post-test microscopy and surface analysis. Much of the work has focused on coating cohesive and adhesive strength, surface fatigue resistance, abrasive wear resistance and friction and wear behaviour under sliding contact and metal cutting conditions.

    The results show that the CVD deposition of accurate crystallographic phases, e.g. α-Al2O3 rather than κ-Al2O3, textures and multilayer structures can increase the wear resistance of Al2O3. However, the characteristics of the interfaces, e.g. topography as well as interfacial porosity, have a strong impact on coating adhesion and consequently on the resulting properties.  Through the deposition of well designed bonding and template layer structures the above problems may be eliminated.

    Also, the presence of macro-particles in PVD coatings may have a significant impact on the interfacial adhesive strength, increasing the tendency to coating spalling and lowering the surface fatigue resistance, as well as increasing the friction in sliding contacts.

    Finally, the CVD-Al2Ocoating topography influences the contact conditions in sliding as well as in metal cutting.

    In summary, the work illuminates the importance of understanding the relationships between deposition process parameters, composition and microstructure, resulting properties and tribological performance of CVD and PVD coatings and how this knowledge can be used to develop the coating materials of tomorrow.

  • 254.
    Fallqvist, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    M’Sauobi, R
    Seco Tools.
    Andersson, J
    Seco Tools.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Mechanical and tribological properties of PVD-coated cemented carbide as evaluated by a new multi-pass scratch testing method2012In: Advances in Tribology, ISSN 1687-5915, E-ISSN 1687-5923, no 305209Article in journal (Refereed)
    Abstract [en]

    A new test method based on multipass scratch testing has been developed for evaluating the mechanical and tribological properties of thin, hard coatings. The proposed test method uses a pin-on-disc tribometer and during testing a Rockwell C diamond stylus is used as the “pin” and loaded against the rotating coated sample. The influence of normal load on the number of cycles to coating damage is investigated and the resulting coating damage mechanisms are evaluated by posttest scanning electron microscopy. The present study presents the test method by evaluating the performance of Ti0.86Si0.14N, Ti0.34Al0.66N, and (Al0.7Cr0.3)2O3 coatings deposited by cathodic arc evaporation on cemented carbide inserts. The results show that the test method is quick, simple, and reproducible and can preferably be used to obtain relevant data concerning the fatigue, wear, chipping, and spalling characteristics of different coating-substrate composites. The test method can be used as a virtually nondestructive test and, for example, be used to evaluate the fatigue and wear resistance as well as the cohesive and adhesive interfacial strength of coated cemented carbide inserts prior to cutting tests.

  • 255.
    Fallqvist, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    The influence of surface defects on the mechanical and tribological properties of VN-based arc-evaporated coatings2013In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 297, no 1-2, p. 1111-1119Article in journal (Refereed)
    Abstract [en]

    The influence of surface defects, i.e., droplets and craters, on the mechanical and tribological properties of arc-evaporated VxN coatings deposited on cemented carbide has been investigated in a scratching contact using a diamond stylus and a sliding contact using a stainless steel pin. Post-test characterisation using 3D optical surface profilometry and scanning electron microscopy was performed in order to investigate the mechanical and tribological response of the coatings. The results show that scratch induced coating cracking mainly is restricted to larger droplets showing a low interfacial bonding to the adjacent coating matrix. The influence of coating defects on the cohesive strength, i.e., the tendency to chipping of small coating fragments, was found to be relatively small. In contrast, the presence of defects may have a significant impact on the interfacial adhesive strength, increasing the tendency to spalling. In sliding contact, surface defects such as droplets and craters have a strong impact on the tribological behaviour of the coatings causing abrasive wear of the less hard counter material surface and material transfer to the coating, both mechanisms affecting the friction characteristics of sliding contact tribo systems.

  • 256.
    Fallqvist, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Ruppi, S
    Abrasive wear of textured-controlled CVD a-Al2O3 coatings2007In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 202, no 4-7, p. 837-843Article in journal (Refereed)
    Abstract [en]

    In the present study the wear resistance of some CVD alpha-Al2O3 coatings with different growth textures, i.e. <0001>, <10<(1)over bar>2> and <10<(1)over bar>4>, and a kappa-Al2O3 coating have been investigated using a micro-abrasion test with diamond particles as the abrasive medium. The results show that the softer kappa-Al2O3 coating shows a higher wear rate as compared with the textured alpha-Al2O3 coatings. Of the latter coatings, the 101¯4 textured a-Al2O3 coating shows the lowest wear rate while the <0001> and <10<(1)over bar>2> textured alpha-Al2O3 coatings show similar wear rate. Two different dominant wear mechanisms, i.e. micro cutting and micro chipping, were observed and the latter mechanism is believed to control the wear rate of the Al2O3 coatings investigated. The results obtained are discussed in relation to the dominant wear mechanisms of the coatings identified using scanning electron microscopy.

  • 257.
    Fallqvist, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Material Science.
    Ruppi, Sakari
    Abrasive wear of multilayer kappa-Al2O3-Ti(C,N) CVD coatings on cemented carbide2007In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 263, no 1-6, p. 74-80Article in journal (Refereed)
    Abstract [en]

    In the present study the wear resistance of kappa-Al2O3–Ti(C,N) multilayer CVD coatings with different multilayer structures (8, 15, 32 layers of kappa-Al2O3 separated by thin Ti(C,N) layers) have been investigated using a micro-abrasion and a cutting test. The results show that the wear rate of the kappa-Al2O3 multilayer coatings tend to decrease with decreasing layer thickness in the micro-abrasion test and decrease with increasing layer thickness in the cutting tests. The reason for this is mainly due to the difference in wear behaviour depending on temperature. The results obtained are discussed in relation to the dominant wear mechanisms of the coatings which have been identified using scanning electron microscopy and energy dispersive X-ray spectroscopy. The potential of the micro-abrasion test in the characterisation of thin CVD coatings for cutting tool applications is discussed.

  • 258.
    Fallqvist, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Ruppi, S
    Seco Tools.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Ottosson, M
    Uppsala Universitet.
    Grehk, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology. Sandvik Materials Technology.
    Nucleation and growth of CVD α-Al2O3on TixOy template2012In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 207, p. 254-261Article in journal (Refereed)
    Abstract [en]

    The microstructure, phase and chemical composition of TixOy templates used to nucleate α-Al2O3 on Ti(C,N) coated cemented carbide have been elucidated using scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. Further, the adhesive strength of the α-Al2O3–TixOy–Ti(C,N) interfaces was investigated using scratch adhesion testing.

    The present study confirmed that the as-deposited template consisted of a Ti4O7 phase which during subsequent deposition of the Al2O3 layer transformed to a Ti3O5 phase and that the grown Al2O3 layer consisted of 100% α-Al2O3. Furthermore, the results showed that the lowest interfacial strength within the multilayer structure was exhibited by the Ti(C,N)–TixOy interface and that the transformation of Ti4O7 to Ti3O5 in the template resulted in formation of pores in the Ti(C,N)-template interface lowering the interfacial strength even more. The use of surface analysis techniques such as Auger electron spectroscopy and especially Time-of-Flight Secondary Ion Mass Spectrometry enabled trace element analyses using depth profiling to characterise the thin interfacial layers in detail.

  • 259.
    Fallqvist, Mikael
    et al.
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Schultheiss, F
    Lunds Universitet.
    Olsson, Mikael
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    M’Sauobi, R
    Seco Tools.
    Ståhl, J E
    Lunds Universitet.
    Influence of CVD Al2O3 coated tool surface micro topography on the tribological characteristics in metal cutting: part I2013In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, p. 87-98Article in journal (Refereed)
    Abstract [en]

    The influence of surface micro topography of CVD α-Al2O3 coatings, deposited on cemented carbide inserts, on tribological characteristics in sliding contact and in metal cutting has been investigated using quenched and tempered steel as counter/work material. Pin-on-disc and turning tests were carried out and post-test characterization using 3D optical surface profilometry and scanning electron microscopy was performed in order to investigate the tribological response of the coatings. The results show that surface micro topography can have a significant impact on the tribological performance of Al2O3 coatings under initial and cutting contact conditions. For both kinds of tests the tendency for transfer of workpiece material strongly increases with increasing coating micro topography. In the pin-on-disc tests, a smooth coating surface significantly reduces the friction coefficient. In the turning tests the contact conditions at the flank face increase with decreasing micro topography. In contrast, no general conclusions can be drawn regarding the influence of coating micro topography on the contact conditions at the rake face. The resulting topography of the turned surface was found to increase with increasing coating topography.

  • 260.
    Farag, Ahmed
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Gabriele, Giovanni
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    A Feasibility Study of Solar-Assisted District Heating in Torsång2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays, using renewable energy, especially solar, is an expanding trend in the Nordic

    countries. In the past few years, the Europian Union has issued energy efficiency directives

    [1] that obligated its member countries to involve 50 % of renewable energies in the

    district heating (DH) networks. This opens the door for the integration of solar energy in

    the existent heat generation plants.

    Borlänge Energi AB, a municipal energy company, owns and operates a DH plant and

    network in Torsång; a small-community village outside Borlänge, in Dalarna County,

    Sweden. The plant generates the required heat using conventional energy boilers fueled by

    wood pellets, grid electricity, and oil. The company suggested using the nearby empty land,

    owned by the municipality, for installing a solar thermal collector field.

    The thesis aims at doing a feasibility study of the possible integration of a solar thermal

    collector field to the existent DH plant in Torsång. The goal is to replace the oil boilers

    with solar energy and to estimate the amount of fuel and emissions that can be saved and

    their effects on economics.

    To achieve the appointed tasks, a planned strategy was developed. After visiting the site

    and collecting all relevant data, the missing hourly load was calculated. Thumb rules were

    used for system sizing. The Polysun simulation software is used to model and simulate the

    proposed system. Two collector models from the same manufacturer were tested. The

    effects of lowering the DH temperature and changing the pellet boiler shut-down period

    were investigated. A sensitivity analysis of the solar fraction was conducted to provide

    different sizing options. In the end, an economic evaluation of the proposed solutions was

    made.

    The results revealed that, for all cases, the oil boilers could be successfully replaced saving

    0.6 m3 of diesel oil and 1.1 ton of CO2 emissions annually. A solar fraction of around 35 %

    was achieved. Shutting down the pellet boiler in the three summer months was proposed

    which reduced its operating time. Consequently, the pellet boiler energy production and

    the fuel consumption reduced by around 36 %. While its CO2 emissions are mitigated by

    26 %.

    The project, from the economic perspective, is showing a competitive value of LCOH

    (between 386 and 423 SEK/MWh) which is lower than the actual cost of the produced

    heat by the plant (500 SEK/MWh). The payback period is quite reasonable with values

    between 24 and 37 years, depending on the chosen solution. Governmental subsidies are

    not taken into consideration in the economic analysis, so the proposed values represent an

    upper boundary, which can be lowered whenever any incentive will be granted to the

    project.

    The proposed system makes room for two possible solutions: the first allows to shut-down

    the pellet boiler for the whole summer, thus giving more flexibility for the maintenance of

    it, benefits in terms of fuel and related emissions saved, but increasing the electricity

    consumption. The second solution, instead, is offering a shorter shut-down time, but with

    more monetary benefits.

  • 261. Fazakas, E.
    et al.
    Heczel, A.
    Molnar, David
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Varga, B.
    Zadorozhnyy, V.
    Vida, A.
    Comparative microstructural and corrosion development of VCrNiCoFeCu equiatomic multicomponent alloy produced by induction melting and spark plasma sintering2018In: IOP Conference Series: Materials Science and Engineering, 2018, Vol. 329, no 1, article id 012016Conference paper (Refereed)
    Abstract [en]

    The present study focuses on the corrosion behavior of a single-phase FCC high entropy alloy (VCrNiCoFeCu) casted by two different methods: induction melting and spark plasma sintering. The corrosion resistance has been evaluated using immersion tests in 3.5% NaCl solution, the potentiodynamic polarization measurements and the results are compared how is dependent the corrosion rate as a function of the production methods. Our results show that induction melted sample is stable in salty environment. On the other hand, based on the changes of polarization curves, there must be an evolution of oxide films on the SPSed sample until reaching the stable oxide layer. 

  • 262.
    Fedorov, Anton
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Photovoltaic System Design for a Contaminated Area in Falun – Comparison of South and East- West Layout2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis the solar part of a large grid-connected photovoltaic system design has been done. The main purpose was to size and optimize the system and to present figures helping to evaluate the prospective project rationality, which can potentially be constructed on a contaminated area in Falun. The methodology consisted in PV market study and component selection, site analysis and defining suitable area for solar installation; and system configuration optimization based on PVsyst simulations and Levelized Cost of Energy calculations.

    The procedure was mainly divided on two parts, preliminary and detailed sizing. In the first part the objective was complex, which included the investigation of the most profitable component combination and system optimization due to tilt and row distance. It was done by simulating systems with different components and orientations, which were sized for the same 100kW inverter in order to make a fair comparison. For each simulated result a simplified LCOE calculation procedure was applied. The main results of this part show that with the price of 0.43 €/Wp thin-film modules were the most cost effective solution for the case with a great advantage over crystalline type in terms of financial attractiveness.

    From the results of the preliminary study it was possible to select the optimal system configuration, which was used in the detailed sizing as a starting point. In this part the PVsyst simulations were run, which included full scale system design considering near shadings created by factory buildings. Additionally, more complex procedure of LCOE calculation has been used here considered insurances, maintenance, time value of money and possible cost reduction due to the system size.

    Two system options were proposed in final results; both cover the same area of 66000 m2. The first one represents an ordinary South faced design with 1.1 MW nominal power, which was optimized for the highest performance. According to PVsyst simulations, this system should produce 1108 MWh/year with the initial investment of 835,000 € and 0.056 €/kWh LCOE. The second option has an alternative East-West orientation, which allows to cover 80% of occupied ground and consequently have 6.6 MW PV nominal power. The system produces 5388 MWh/year costs about 4500,000 € and delivers electricity with the same price of 0.056 €/kWh. Even though the EW solution has 20% lower specific energy production, it benefits mainly from lower relative costs for inverters, mounting and annual maintenance expenses.

    After analyzing the performance results, among the two alternatives none of the systems showed a clear superiority so there was no optimal system proposed. Both, South and East-West solutions have own advantages and disadvantages in terms of energy production profile, configuration, installation and maintenance. Furthermore, the uncertainty due to cost figures assumptions restricted the results veracity.

  • 263. Fedrizzi, Roberto
    et al.
    Dipasquale, Chiara
    Bellini, Alessandro
    Gustafsson, Marcus
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Ochs, Fabian
    Dermentzis, Georgios
    Nouvel, Romain
    Cotrado, Mariela
    D6.3a Performance of the Studied Systemic Renovation Packages - Method2015Report (Other academic)
    Abstract [en]

    One of the primary objectives of the iNSPiRe project was to develop a tool that predicts the energy and cost saving impacts of various systemic retrofit interventions. This tool is now available for all those involved in the renovation of older buildings (from consulting offices, moving through construction companies and to decision makers) to use as a means of selecting which retrofit package will deliver the greatest costs savings and most improved energy efficiencies.To this purpose, we have produced three databases that provide valuable information about the energy performance of a variety of buildings in different climates, based on different energy requirements. These are the results of a three stage process:1. Collection of energy use data (statistics) for the whole of EU 27, the structuring of a building stock database and the definition of reference buildings that represent the most typical buildings of the building stock. Data for six different age categories were derived, including typical construction information and insulation standards for these periods. Seven climatic regions were also defined to cover the EU 27. The structured data are available in the Building Stock Statistics database.2. Derivation of a complete and consistent database of heating and cooling demands in residential and office buildings covering the whole of the EU 27 based on the simulation of the defined reference buildings in seven climatic regions. The simulations were calibrated against the energy use statistics, and are thus consistent with these, but offer the full range of heating and cooling demands for all climates and building types for six different age categories. The results are available in the Reference Building Simulation database.3. Definition of a range of retrofit measures for the reference buildings including climatic shell, HVAC system and heating/cooling distribution. The matrix of these measures was then simulated for all building types for the seven different climatic regions to provide data for the third database, the Systemic Renovation Packages database.

  • 264. Fedrizzi, Roberto
    et al.
    Dipasquale, Chiara
    Bellini, Alessandro
    Gustafsson, Marcus
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Ochs, Fabian
    Dermentzis, Georgios
    Nouvel, Romain
    Cotrado, Mariela
    D6.3b Performance of the Studied Systemic Renovation Packages - Single Family Houses2015Report (Other academic)
    Abstract [en]

    One of the primary objectives of the iNSPiRe project was to develop a tool that predicts the energy and cost saving impacts of various systemic retrofit interventions. This tool is now available for all those involved in the renovation of older buildings (from consulting offices, moving through construction companies and to decision makers) to use as a means of selecting which retrofit package will deliver the greatest costs savings and most improved energy performance.The whole set of Renovation Packages in the published database includes results for a range of SFH typologies, from detached to row houses, with different external surface over building volume ratio.In order to compare the same Envelope Renovation when applied to different SFH typologies and climates, we adopted the detached constructions as the basis to define insulation, windows and mechanical ventilation measures that match the heating demand standards sought (15, 25, 40, 70 kWh/m2y). Since the solutions found are the most conservative, lower heating demands are obtained for semi-detached and row houses.The solutions elaborated in terms of window features, and walls/roof cross sections and materials, are reported in Deliverable 6.3a for the whole range of buildings and the 7 climates analysed.In this document we comment the results relative to the reference buildings built 1945-1970, renovated with four generation systems (AWHP, GWHP, gas boiler and biomass boiler) and three distribution systems (radiant ceilings, radiators and fan coils). In order to limit the number of solutions discussed, here we report results only for the detached SFHs. The full range of solutions is published on the iNSPiRe website.The generation plants are hybrid solutions designed to combine heat pumps or boilers with solar thermal and/or PV technologies. These combinations integrate multiple renewable energy sources, thus allowing to reach in the best cases the 50 kWh/m2y primary energy consumption limit that is the objective of the retrofit packages devised.

  • 265. Fedrizzi, Roberto
    et al.
    Dipasquale, Chiara
    Bellini, Alessandro
    Gustafsson, Marcus
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Ochs, Fabian
    Dermentzis, Georgios
    Nouvel, Romain
    Cotrado, Mariela
    D6.3c Performance of the Studied Systemic Renovation Packages - Multi-Family Houses2015Report (Other academic)
    Abstract [en]

    In this report, we comment the results relative to the reference buildings built within the first age (1945-1970), and renovated with 4 generation systems (air to water heat pump, ground water heat pump, gas boiler and biomass boiler) and 3 distribution systems (radiant ceilings, radiators and fan coils).According to the buildings classification (see D2.1a and D2.1c), two different Multi Family Houses typologies are identified, small Multi Family House (s-MFH) and large Multi Family House (l-MFH). In the published database, only s-MFHs are included, varying the number of floors (3, 5 and 7 floors) and, consequently, the surface over volume (S/V) ratio.As well as for the SFHs, we adopted a reference S/V ratio as the basis to define insulation, windows and mechanical ventilation measures to match the sought heating demand targets (15, 25, 45, 70 kWh/m²y), that is 5 floors and 10 apartments.

  • 266.
    Fiedler, Frank
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    A testing and demonstration facility for PV systems and components2013In: Proceedings of 3rd Symposium Small PV Applications: Rural Electrification and commercial use / [ed] OTTI e.V., Regensburg, Germany, 2013, p. 111-116Conference paper (Other academic)
    Abstract [en]

    A test and demonstration facility for PV and PV hybrid systems and system components has been designed and installed at Dalarna University in Sweden. The facility allows studies of complete PV systems or single components in a range of 0.1-10 kW. The facility includes two grid-connected PV systems, a PV Hybrid off-grid system, three emulators and the necessary measurement and control equipment. Tests can be done manually or automatically through programmed test procedures controlled that will be implemented in Labview. The facility shall be used by researchers, professionals of the industry and engineering students.

  • 267.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Persson, Jannika
    Dalarna University, School of Technology and Business Studies, Construction.
    Gustavsson, Marcus
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Kovacs, Peter
    RISE.
    Hemlin, Olleper
    RISE.
    Ollas, Patrik
    RISE.
    Thuvander, Liane
    Chalmers Tekniska Högskolan.
    Femenías, Paula
    Chalmers Tekniska Högskolan.
    Lundin, Michelle
    Chalmers Tekniska Högskolan.
    Larsson, David
    Solkompaniet.
    Miljontak Delprojekt 2: Sammanfattning av litteratursammanställning2018Report (Other academic)
  • 268.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Optimisation method for solar heating systems in combination with pellet boilers/stoves2007In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 4, no 3, p. 325-337Article in journal (Refereed)
    Abstract [en]

    In this study an optimisation method for the design of combined solar and pellet heating systems is presented and evaluated. The paper describes the steps of the method by applying it for an example system. The objective of the optimisation was to find the design parameters that give the lowest auxiliary energy (pellet fuel + auxiliary electricity) and carbon monoxide (CO) emissions for a system with a typical load, a single family house in Sweden. Weighting factors have been used for the auxiliary energy use and CO emissions to give a combined objective function. Different weighting factors were tested. The results show that extreme weighting factors lead to their own minima. However, it was possible to find factors that ensure low values for both auxiliary energy and CO emissions, and suitable weighting factors are suggested.

  • 269.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Comparison of carbon monoxide emissions and electricity consumption of modulating and non-modulating pellet and solar heating systems2007In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 31, no 10, p. 915-930Article in journal (Refereed)
    Abstract [en]

    Emission and electricity consumption are important aspects of a pellet heating system. Low noxious emissions, particularly carbon monoxide, are a measure of a well-performing system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner, poor adjustment of the combustion air and insufficient maintenance. The carbon monoxide output, the thermal performance and the electricity consumption for modulating and non-modulating operation mode have been investigated by simulations of four stoves/boilers as part of combined solar and pellet heating systems. The systems have been modelled with the simulation programme TRNSYS and simulated with the boundary conditions for space heating demand, hot water load and climate data as used in earlier research projects. The results from the simulations show that operating the pellet units with modulating combustion power reduces the number of starts and stops but does not necessarily reduce the carbon monoxide output. Whether the carbon monoxide output can be reduced or not depends very strongly on the reduction of starts and stops and how much the carbon monoxide emissions increase with decreased combustion power, which are in turn dependent on the particular settings of each pellet burner and how the heat is transferred to the building. However, for most systems the modulating operation mode has a positive impact on carbon monoxide emissions. Considering the total auxiliary energy demand, including the electricity demand of the pellet units, the modulating combustion control is advantageous for systems 1 and 4 for the used boundary conditions. The study also shows that an appropriate sizing of the stove or boiler has a huge potential for energy saving and carbon monoxide emission reduction.

  • 270.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Vestlund, Johan
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Monitoring results of combined pellet and solar heating system2007In: ISES Solar World Congress 2007, ISES 2007, 2007, Vol. 2, p. 867-871Conference paper (Other academic)
    Abstract [en]

    In this study the monitoring results of prototype installation of a recently developed solar combisystem have been evaluated. The system, that uses a water jacketed pellet stove as auxiliary heater, was installed in a single family house in Borlänge/Sweden. In order to allow an evaluation under realistic conditions the system has been monitored for a time period of one year. From the measurements of the system it could be seen that it is important that the pellet stove has a sufficient buffer store volume to minimize cycling. The measurements showed also that the stove gives a lower share of the produced heat to the water loop than measured under stationary conditions. The solar system works as expected and covers the heat demand during the summer and a part of the heat demand during spring and autumn. Potential for optimization exists for the parasitic electricity demand. The system consumes 680 kWh per year for pumps, valves and controllers which is more than 4% of the total primary heating energy demand.

  • 271.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Nielsen, Caroline
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Design Study of a PV-Diesel Hybrid System for a Micro-Grid in Tanzania2012Conference paper (Other academic)
    Abstract [en]

    In 2008 a micro PV-Diesel Hybrid system has been installed at the Ihushi Development Center (IDC) near Mwanza in Tanzania. In April 2011 a monitoring system was installed at IDC to study the system performance and the usage of the system. Measured data from April to July 2011 have been used to model the system with the simulation software HOMER. One question was if HOMER allows accurate modelling and simulations of the actual system. In addition, it has been studied if the current system can be optimized and what system design solutions are most promising when the system need to be redesigned for a higher load.

  • 272.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Thermal performance of combined solar and pellet heating systems2006In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 31, no 1, p. 73-88Article in journal (Refereed)
    Abstract [en]

    Various pellet heating systems are marketed in Sweden, some of them in combination with a solar heating system. Several types of pellet heating units are available and can be used for a combined system. This article compares four typical combined solar and pellet heating systems: System 1 and 2 with a pellet stove, system 3 with a store integrated pellet burner and system 4 with a pellet boiler. The often lower efficiency of pellet heaters compared to oil or gas heaters increases the final energy demand. Consequently heat losses of the various systems have been studied. The systems have been modeled in TRNSYS and simulated with parameters identified from measurements. For almost all systems the flue gas losses are the main heat losses except for system 3 where store heat losses prevail. Relevant are also the heat losses of the burner and the boiler to the ambient. Significant leakage losses are noticed for system 3 and 4. For buildings with an open internal design system 1 is the most efficient solution. Other buildings should preferably apply system 2 or 3. The right choice of the system depends also on whether the heater is placed inside or outside of the heated area. Unlike the expectations and results from other studies, the operation of the pellet heaters with modulating combustion power is not necessarily improving the performance. A large potential for system optimization exists for all studied systems, which when applied could alter the relative merits of the different system types.

  • 273.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Annual CO-emissions of combined pellet and solar heating systems2007In: ISES Solar World Congress 2007, ISES 2007, 2007, Vol. 4, p. 2468-2472Conference paper (Other academic)
    Abstract [en]

    Emissions are an important aspect of a pellet heating system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner when the burner is operated below the lowest combustion power. Combining pellet heating systems with a solar heating system can significantly reduce cycling of the pellet heater and avoid the inefficient summer operation of the pellet heater. The aim of this paper was to study CO-emissions of the different types of systems and to compare the yearly CO-emissions obtained from simulations with the yearly CO-emissions calculated based on the values that are obtained by the standard test methods. The results showed that the yearly CO-emissions obtained from the simulations are significant higher than the yearly CO-emissions calculated based on the standard test methods. It is also shown that for the studied systems the average emissions under these realistic annual conditions were greater than the limit values of two Eco-labels. Furthermore it could be seen that is possible to almost halve the CO-emission if the pellet heater is combined with a solar heating system.

  • 274.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Carbon monoxide emissions of combined pellet and solar heating systems2009In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, no 2, p. 135-143Article in journal (Refereed)
    Abstract [en]

    Emissions are an important aspect of a pellet heating system. Low harmful emissions, particularly carbon monoxide, are a measure of a well performing system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner and when the average load is below the lowest possible combustion power of the burner. Combining pellet heaters with a solar heating system can significantly reduce cycling of the pellet heater and avoid the inefficient summer operation of the pellet heater. Five combined systems representing the range of typical solutions of this system type and one recently developed system have been studied, modelled and simulated. These systems are compared to a reference system, which is based on a pellet boiler and is not combined with a solar heating system. The aim was to study CO-emissions of the different types of systems and to analyse the potential of CO-emission reduction when the pellet heater is combined with a solar heating systems. Another aim was to compare the yearly CO-emissions obtained from simulations under realistic dynamic conditions with the yearly CO-emissions calculated based on the values that are obtained by the standard test methods. The study was performed with the simulation tool TRNSYS. The parameter used in the study have been identified from lab measurements on existing pellet boilers/stoves and solar heating systems. The results from the simulations show that it is possible to almost halve the CO-emission if the pellet heater is combined with a solar heating system. The results also show that the CO-emission of existing combined solar and pellet heating systems can be drastically reduced if the pellet heater is properly controlled and some basic design rules are observed. This can also be seen when analyzing the results for the new system concept where these rules have been taken into account. Comparing the yearly CO-emissions obtained from the simulations with the yearly CO-emissions calculated based on the standard test methods shows that using the latter give too low CO-values for the whole year. It is also shown that for the existing systems the average emissions under these realistic annual conditions were greater than the limit values of two Eco-labels.

  • 275.
    Filatov, Artem
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Concentrating Collector for Torsång District Heating System2018Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis report for Dalarna University in Borlange and Absolicon company the study of a possibility to add an array of concentrating solar collectors to a Torsång district heating system was done. The whole idea of this work was to make a simulation of this kind of system, trying to get 15-20% of solar fraction, and make an economical evaluation.

    At the same time, another goal was to make two comparisons: between concentrating and flat-plate collector in the same system, and between two tools for collector analysis – Polysun and Absolicon tool, based on TRNSYS, which was designed to estimate the output of the collector for a certain temperature, without any load.

    During the study, the analysis of the simulating tools was made and the combination of those two tools was used. Using long iteration cycles, involving changing the field layout, number of collectors and distance between collector rows in flat-plate collector case, both types of collectors were analyzed. The method of the analysis was to get an equal output of the field and see the differences, which appear while using different collector types.

  • 276. Filipovic, Mirjana
    et al.
    Jonsson, Stefan
    Dalarna University, School of Technology and Business Studies, Material Science.
    Experimental and numerical study of the evolution of artificial inner defects in stainless steel rolled in a wire rod block2009Manuscript (preprint) (Other academic)
    Abstract [en]

    The evolution of a central longitudinal defect was investigated for an austenitic stainless steel of type AISI 304L by preparing 12.5 mm round bars with a 4 mm round hole of length 100 mm. The evolution was monitored by taking out bars, rolled 1, 1+2, 1+2+3 passes and so on, from a wire rod block operated at a final exiting speed of 60 m/s. Cross sections of the rolled bars through the central defect were investigated with respect to geometrical changes and microstructure. The rolling process of the first 4 passes were analysed with FEM. The results show good agreement between simulations and experiments. In general, the defect is reduced quicker in size than predicted by a pure geometrical scaling. The analyses show that the round passes are more effective in reducing the defect size than the ovals. The velocity changes imposed by the central defect closing and reopening is analysed.

  • 277.
    Finnkvist Penttinen, Anna
    Dalarna University, School of Technology and Business Studies, Materials Technology.
    Nötningsbeständighet av bestrykningsschaber2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A study of the type of wears Böhler‐Uddeholms coating blades are subjected to when

    they are considered to be consumed to handle usage. Their own devices on the

    company in order to determine the abrasion resistance on the coater blades was

    comparable to the pin‐on‐disc application.

    This is to possibly find a standard way to measure the wear of the different blades

    with the currently available application. If one were to succeed in finding a way this

    will result in that one can give customers with more information on the blades and

    give a better customer service.

    Two end‐used coater blades were used to determine the wear that has occurred.

    For the investigation between Böhler‐Uddeholms device and the pin‐on‐disc

    application three different steel blades were used, named Steel |, steel || and

    steel ||| in this rapport.

    The final wear that occurred on the blades was three body abrasion and corrosive

    wear. It will also, because of the basic coating mass, build an adhesive border along

    the edge of the coating blade.

    The apparatus of the company is in the current situation not quite optimal to mimic

    the actual wear that occurs. The pin‐on‐disc application gives a harder abrasive wear

    that can sees in the wear in the industries at the end use.

  • 278. Fisk, Martin
    et al.
    Hansson, Sofia
    Dalarna University, School of Technology and Business Studies, Material Science.
    FE-Simulation of combined induction heating and extrusion in manufacturing of stainless steel tubes2009In: Computational Plasticity (COMPLAS) X: Fundamentals and Applications: proceedings of the tenth International Conference on Computational Plasticity held in Barcelona, Spain, 2th-4th September 2009 / [ed] E. O˜nate and D.R.J. Owen, Barcelona: International Center for Numerical Methods , 2009Conference paper (Refereed)
    Abstract [en]

    The manufacturing process chain for extrusion of AISI 316L tubes is simulatedusing the finite element method. Models of induction heating and expansion is included and thetemperature field in the billet before extrusion is calculated. It is shown that a correct initialtemperature of the billet is needed in order to predict the extrusion force curve in the initialstage of the process.

  • 279. Fleury, E.
    et al.
    Jayamani, Jayaraj
    Kim, Y. C.
    Seok, H. K.
    Kim, K. Y.
    Kim, K. B.
    Fe-based amorphous alloys as bipolar plates for PEM fuel cell2006In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 159, no 1, p. 34-37Article in journal (Refereed)
    Abstract [en]

    Two compositions of Fe-based Fe50Cr18Mo8Al2Y2C14B6 and Fe44Cr15Mo14Y2C15B6N4 amorphous alloys were developed as alternative bipolar plate material for polymer electrolyte membrane fuel cell (PEMFC). In this paper, we present results of an investigation on the electrical, mechanical, corrosion properties and processing ability of these amorphous alloys. The combination of excellent properties indicated that Fe-based amorphous alloys could be potential candidate materials as bipolar plates in PEMFC.

  • 280.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Color detection and segmentation for road and traffic signs2004In: IEEE Conference on Cybernetics and Intelligent Systems, 2004. / [ed] IEEE, Singapore, 2004, Vol. 2, p. 809-814Conference paper (Refereed)
    Abstract [en]

    This paper aims to present three new methods for color detection and segmentation of road signs.  The images are taken by a digital camera mounted in a car.  The RGB images are converted into IHLS color space, and new methods are applied to extract the colors of the road signs under consideration. The methods are tested on hundreds of outdoor images in different light conditions, and they show high robustness. This project is part of the research taking place in Dalarna University / Sweden in the field of the ITS.

  • 281.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Segmentation and enhancement of low quality fingerprint images2016In: Web Information Systems Engineering – WISE 2016: 17th International Conference, Shanghai, China, November 8-10, 2016, Proceedings, Part II, China - Shanghai: Springer, 2016, Vol. 10042, p. 371-384Conference paper (Refereed)
    Abstract [en]

    This paper presents a new approach to segment low quality finger-print images which are collected by low quality fingerprint scanners. Images collected using such readers are easy to collect but difficult to segment. The proposed approach focuses on automatically segment and enhance these fingerprint images to reduce the detection of false minutiae and hence improve the recognition rate. There are four major contributions of this paper. Firstly, segmentation of fingerprint images is achieved via morphological filters to find the largest object in the image which is the foreground of the fingerprint. Secondly, specially designed adaptive thresholding algorithm to deal with fingerprint images. The algorithm tries to fit a curve between the gray levels of the pixels of each row or column in the fingerprint image. The curve represents the binarization threshold of each pixel in the corresponding row or column. Thirdly, noise reduction and ridge enhancement is achieved by invoking a rotational invariant anisotropic diffusion filter. Finally, an adaptive thinning algorithm which is immune against spurs is invoked to generate the recognition ready fingerprint image. Segmentation of 100 images from databases FVC2002 and FVC2004 was performed and the experiments showed that 96 % of images under test are correctly segmented.

  • 282.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Traffic Sign detection and recognition2017In: Computer Vision and Imaging in Intelligent Transportation Systems, John Wiley & Sons, 2017, 1, p. 343-374Chapter in book (Refereed)
    Abstract [en]

    This chapter presents an overview of traffic sign detection and recognition. It describes the characteristics of traffic signs and the requirements and difficulties when dealing with traffic sign detection and recognition in outdoor images. The chapter also covers the different techniques invoked to segment traffic signs from the different traffic scenes and the techniques employed for the recognition and classification of traffic signs. It points many problems regarding the stability of the received colour information, variations of these colours with respect to the daylight conditions, and absence of a colour model that can led to a good solution. It also proposes an adaptive colour segmentation model based on Neural Networks. The chapter demonstrates the way to classify segmented traffic signs by employing one of widely used classifiers, AdaBoost , based on a set of features, in this case HOG descriptors, which was developed for pedestrian recognition but found the way for many applications in different fields. The chapter ends by showing examples where traffic sign recognition is applicable in vehicle industry

  • 283.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Traffic sign recognition without color information2015Report (Other academic)
    Abstract [en]

    Color represents an important attribute in the field of traffic sign recognition. However, when the color of the traffic sign fades or the traffic scene is collected in gray as in the case of Infrared imaging, then color based recognition systems fail. Other problems related to color are simply that different countries use different colors. Even within the European Union, colors of traffic signs are not the same.

    This paper aims to present a new approach to detect traffic signs without color attributes. It is based a two-stage sliding window which detects traffic signs in the multi-scale image. Histogram of Oriented Gradients (HOG) descriptors are computed as a quality function which are evaluated by two SVM classifier; the coarse and the fine detectors. 

    Different objects detected by the coarse detectors are clustered and a fine search is conducted in the areas where traffic signs are more probable to exist. 

    Experiments conducted to detect traffic signs under different light conditions such as sunny, cloudy, fog and snow fall have showed a performance of 98% and very low false positive rate.  The proposed approach was tested on the Yield traffic signs because it has a simple triangular shape which can be found in many places other than the traffic signs and represent a challenge to the proposed approach.

  • 284.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Traffic sign recognition without color information2015In: Colour and Visual Computing Symposium (CVCS), 2015 / [ed] Pedersen, M; Thomas, JB, IEEE conference proceedings, 2015, p. 1-6Conference paper (Refereed)
    Abstract [en]

    Color represents an important attribute in the field of traffic sign recognition. However, when the color of the traffic sign fades or the traffic scene is collected in gray as in the case of Infrared imaging, then color based recognition systems fail. Other problems related to color are simply that different countries use different colors. Even within the European Union, colors of traffic signs are not the same. This paper aims to present a new approach to detect traffic signs without color attributes. It is based a two-stage sliding window which detects traffic signs in the multi-scale image. Histogram of Oriented Gradients HOG descriptors are computed as a quality function which are evaluated by two SVM classifier; the coarse and the fine detectors. Different objects detected by the coarse detectors are clustered and a fine search is conducted in the areas where traffic signs are more probable to exist. Experiments conducted to detect traffic signs under different light conditions such as sunny, cloudy, fog and snow fall have showed a performance of 98% and very low false positive rate. The proposed approach was tested on the Yield traffic signs because it has a simple triangular shape which can be found in many places other than the traffic signs which represent a challenge to the proposed approach.

  • 285.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Traffic Signs Color Detection and Segmentation in Poor Light Conditions2005In: Machine Vision Applications (MVA2005), Tsukuba Science City, 2005Conference paper (Refereed)
    Abstract [en]

    This paper presents a new algorithm for color detection and segmentation of road signs in poor light conditions. The images were taken by a digital camera mounted in a car. The RGB channels of the digital images were enhanced separately by histogram equalization, and then a color constancy algorithm was applied to extract the true colors of the sign. The resultant image was then converted into HSV color space, and segmented to extract the colors of the road signs. The method was tested on outdoor images in different poor light conditions such as fog and snow, and they show high robustness. This project is part of the research taking place at Dalarna University - Sweden in the field of the Intelligent Transport Systems (ITS).

  • 286.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Barsam, Payvar
    Optimization of cable cycles: a trade-off between reliability and cost2015In: American Journal of Intelligent Systems, ISSN 2165-8978, E-ISSN 2165-8994, Vol. 5, no 2, p. 43-57Article in journal (Refereed)
    Abstract [en]

    This paper elaborates the routing of cable cycle through available routes in a building in order to link a set of devices, in a most reasonable way. Despite of the similarities to other NP-hard routing problems, the only goal is not only to minimize the cost (length of the cycle) but also to increase the reliability of the path (in case of a cable cut) which is assessed by a risk factor. Since there is often a trade-off between the risk and length factors, a criterion for ranking candidates and deciding the most reasonable solution is defined. A set of techniques is proposed to perform an efficient and exact search among candidates. A novel graph is introduced to reduce the search-space, and navigate the search toward feasible and desirable solutions. Moreover, admissible heuristic length estimation helps to early detection of partial cycles which lead to unreasonable solutions. The results show that the method provides solutions which are both technically and financially reasonable. Furthermore, it is proved that the proposed techniques are very efficient in reducing the computational time of the search to a reasonable amount.

  • 287.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Bhuiyan, Nizam
    Biswas, Rubel
    Prohibitory traffic signs detection using LVQ and windowed Hough transform2011In: IICAI-11 (5 th Indian International Conference on Artificial Intelligence), Tumkur, India, 2011Conference paper (Refereed)
    Abstract [en]

    Prohibitory traffic signs represent an important group of traffic signs which are used to prohibit certain types of manoeuvres or some types of traffic. Speed limits signs belong to this group and speed is the main cause of many deadly accidents. Detecting this group in good time may be helpful to avoid many fatal accidents. This paper presents a new approach to detecting prohibitory traffic signs which is based on colour segmentation using LVQ and windowed Hough Transform. Experiments conducted to check the robustness of this approach indicated that 98.5% of the traffic signs invoked for this test were successfully detected. This test was carried out using images collected under a wide range of environmental conditions.

  • 288.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Bin Mumtaz, Al Hasanat
    Adaptive Shadow and Highlight Invariant Colour Segmentation for Traffic Sign Recognition Based on Kohonen SOM2011In: Journal of Intelligent Systems, ISSN 2191-026X, Vol. 20, no 1, p. 15-31Article in journal (Refereed)
    Abstract [en]

    This paper describes an intelligent algorithm for traffic sign recognition which converges quickly, is accurate in its segmentation and adaptive in its behaviour. The proposed approach can segment images of traffic signs in different lighting and environmental conditions and in different countries. It is based on using Kohonen's Self-Organizing Maps (SOM) as a clustering tool and it is developed for Intelligent Vehicle applications. The current approach does not need any prior training. Instead, a slight portion, which is about 1% of the image under investigation, is used for training. This is a key issue to ensure fast convergence and high adaptability. The current approach was tested by using 442 images which were collected under different environmental conditions and from different countries. The proposed approach shows promising results; good improvement of 73% is observed in faded traffic sign images compared with 53.3% using the traditional algorithm. The adaptability of the system is evident from the segmentation of the traffic sign images from various countries where the result is 96% for the nine countries included in the test.

  • 289.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Biswas, Rubel
    Davami, Erfan
    Traffic sign detection based on AdaBoost color segmentation and SVM classification2013In: Eurocon 2013: IEEE Conference Publications / [ed] IEEE, 2013, p. 2005-2010Conference paper (Refereed)
    Abstract [en]

    This paper aims to present a new approach to detect traffic signs which is based on color segmentation using AdaBoost binary classifier and circular Hough Transform.The Adaboost classifier was trained to segment traffic signs images according to the desired color. A voting mechanism was invoked to establish a property curve for each of the candidates. SVM classifier was trained to classify the property curves of each object into their corresponding classes.

    Experiments conducted on Adaboost color segmentation under different light conditions such as sunny, cloudy, fog and snow fall have showed a performance of 95%. The proposed system was tested on two different groups of traffic signs; the warning and the prohibitory signs. In the case of warning signs, a recognition rate of 98.4% was achieved while it was 97% for prohibitory traffic signs. This test was carried out under a wide range of environmental conditions.

  • 290.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Davami, Erfan
    Eigen Based Traffic Sign Recognition Which Aids In Achieving Intelligent Speed Adaptation2011In: Journal of Intelligent Systems, ISSN 2191-026X, Vol. 20, no 2, p. 129-145Article in journal (Refereed)
    Abstract [en]

    Speed is one of the major factors by which the traffic safety is affected. If the speed limit traffic signs on the road are recognised and displayed to a driver, this will be a motivation to keep the vehicle's speed within the permitted range. The purpose of this paper is to investigate Eigen-based traffic sign recognition which can aid in the development of Intelligent Speed Adaptation. This system is based on invoking the PCA technique to detect the unknown speed limit traffic sign and computes its best effective Eigen vectors. The traffic sign is then recognized and classified by using the shortest Euclidean distance to the different speed limit traffic sign classes. The system was trained using 24 037 images which were collected in different light conditions. To check the robustness of this system, it was tested against 1429 images and it was found that the accuracy of recognition was 97.5% which indicates clearly the high robustness targeted by this system.

  • 291.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Davami, Erfan
    University of Central Florida.
    Multiclass Adaboost Based on an Ensemble of Binary Adaboosts2013In: American Journal of Intelligent Systems, ISSN 2165-8978, E-ISSN 2165-8994, Vol. 3, no 2, p. 57-70Article in journal (Refereed)
    Abstract [en]

    This paper presents a multi-class AdaBoost based on incorporating an ensemble of binary AdaBoosts which is organized as Binary Decision Tree (BDT). It is proved that binary AdaBoost is extremely successful in producing accurate classification but it does not perform very well for multi-class problems. To avoid this performance degradation, the multi-class problem is divided into a number of binary problems and binary AdaBoost classifiers are invoked to solve these classification problems. This approach is tested with a dataset consisting of 6500 binary images of traffic signs. Haar-like features of these images are computed and the multi-class AdaBoost classifier is invoked to classify them. A classification rate of 96.7% and 95.7% is achieved for the traffic sign boarders and pictograms, respectively. The proposed approach is also evaluated using a number of standard datasets such as Iris, Wine, Yeast, etc. The performance of the proposed BDT classifier is quite high as compared with the state of the art and it converges very fast to a solution which indicates it as a reliable classifier.

  • 292.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Davami, Erfan
    Jomaa, Diala
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Segmentation of fingerprint images based on bi-level processing using fuzzy rules2012In: Fuzzy Information Processing Society (NAFIPS), 2012 Annual Meeting of the North American, 2012, p. 1-6Conference paper (Refereed)
    Abstract [en]

    This paper presents a new approach to segment low quality fingerprint images which are collected by low quality fingerprint readers. Images collected using such readers are easy to collect but difficult to segment. The proposed approach is based on combining global and local processing to achieve segmentation of fingerprint images. On the global level, the fingerprint is located and extracted from the rest of the image by using a global thresholding followed by dilation and edge detection of the largest object in the image. On the local level, fingerprint's foreground and its border image are treated using different fuzzy rules which the two images are segmented. These rules are based on the mean and variance of the block under consideration. The approach is implemented in three stages; preprocessing, segmentation, and post-processing. Segmentation of 100 images was performed and compared with manual examinations by human experts. The experiments showed that 96% of images under test are correctly segmented. The results from the quality of segmentation test revealed that the average error in block segmentation was 2.84% and the false positive and false negatives were approximately 1.4%. This indicates the high robustness of the proposed approach.

  • 293.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Jomaa, Diala
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Segmentation of low quality fingerprint images2010Conference paper (Refereed)
    Abstract [en]

    This paper presents a new algorithm to segment fingerprint images. The algorithm uses four features, the global mean, the local mean, variance and coherence of the image to achieve the fingerprint segmentation. Based on these features, a rule based system is built to segment the image. The proposed algorithm is implemented in three stages; pre-processing, segmentation, and post-processing. Gaussian filter and histogram equalization are applied in the pre-processing stage. Segmentation is applied using the local features. Finally, fill the gaps algorithm and a modified version of Otsu thresholding are invoked in the post-processing stage. In order to evaluate the performance of this method, experiments are performed on FVC2000 DB1. Segmentation of 100 images is performed and compared with manual examinations of human experts. It shows that the proposed algorithm achieves a correct segmentation of 82% of images under test.

  • 294.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Jomaa, Diala
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Davami, Erfan
    Segmentation of fingerprint images based on bi-level combination of global and local processing2012In: Journal of Intelligent Systems, ISSN 2191-026X, Vol. 21, no 2, p. 97-120Article in journal (Refereed)
    Abstract [en]

    This paper presents a new approach to segment low quality fingerprint imageswhich are collected by low quality fingerprint readers. Images collected using such readersare easy to collect but difficult to segment. The proposed approach is based on combiningglobal and local processing to achieve segmentation of fingerprint images. On the globallevel, the fingerprint is located and extracted from the rest of the image by using a globalthresholding followed by dilation and edge detection of the largest object in the image.On the local level, fingerprint’s foreground and its border image are treated using differentfuzzy rules. These rules are based on the mean and variance of the block under consideration.The approach is implemented in three stages: pre-processing, segmentation, andpost-processing.Segmentation of 100 images was performed and compared with manual examinationsby human experts. The experiments showed that 96% of images under test are correctlysegmented. The results from the quality of segmentation test revealed that the averageerror in block segmentation was 2.84% and the false positive and false negatives wereapproximately 1.4%. This indicates the high robustness of the proposed approach.

  • 295.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Khan, Taha
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Pattern matching approach towards real-time traffic sign recognition2010Conference paper (Refereed)
    Abstract [en]

    This paper addresses the problem of traffic sign recognition in real-time conditions. The algorithm presented in this paper is based on detecting traffic signs in life images and videos using pattern matching of the unknown sign’s shape with standard shapes of the traffic signs. The pattern matching algorithm works with shape vertices rather than the whole image. This reduces the computation time which is a crucial factor to fit real-time demands. The algorithm is translation and scaling invariant. It shows high robustness as it is tested with 500 images and several videos and a recognition rate of 97% is achieved.

  • 296.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Mohammed, Iman
    Night time vehicle detection2012In: Journal of Intelligent Systems, ISSN 0334-1860, Vol. 21, no 2, p. 143-165Article in journal (Refereed)
    Abstract [en]

    Night driving is one of the major factors which affects traffic safety. Althoughdetecting oncoming vehicles at night time is a challenging task, it may improve trafficsafety. If the oncoming vehicle is recognised in good time, this will motivate drivers tokeep their eyes on the road. The purpose of this paper is to present an approach to detectvehicles at night based on the employment of a single onboard camera. This system isbased on detecting vehicle headlights by recognising their shapes via an SVM classifierwhich was trained for this purpose. A pairing algorithm was designed to pair vehicleheadlights to ensure that the two headlights belong to the same vehicle. A multi-objecttracking algorithm was invoked to track the vehicle throughout the time the vehicle isin the scene. The system was trained with 503 single objects and tested using 144 587single objects which were extracted from 1410 frames collected from 15 videos and 27moving vehicles. It was found that the accuracy of recognition was 97.9% and the vehiclerecognition rate was 96.3% which indicates clearly the high robustness attained by thissystem.

  • 297.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Roch, Janina
    TU Kaiserslautern, Kaiserslautern, Germany.
    Benchmark Evaluation of HOG Descriptors as Features for Classification of Traffic Signs2013Report (Other academic)
    Abstract [en]

    The purpose of this paper is to analyze the performance of the Histograms of Oriented Gradients (HOG) as descriptors for traffic signs recognition. The test dataset consists of speed limit traffic signs because of their high inter-class similarities.

      HOG features of speed limit signs, which were extracted from different traffic scenes, were computed and a Gentle AdaBoost classifier was invoked to evaluate the different features. The performance of HOG was tested with a dataset consisting of 1727 Swedish speed signs images. Different numbers of HOG features per descriptor, ranging from 36 features up 396 features, were computed for each traffic sign in the benchmark testing. The results show that HOG features perform high classification rate as the Gentle AdaBoost classification rate was 99.42%, and they are suitable to real time traffic sign recognition. However, it is found that changing the number of orientation bins has insignificant effect on the classification rate. In addition to this, HOG descriptors are not robust with respect to sign orientation.

  • 298.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Westin, Jerker
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Extracting Body Landmarks from Videos for Parkinson Gait Analysis2019In: Proceedings - IEEE Symposium on Computer-Based Medical Systems, 2019, Vol. 2019-June, p. 379-384, article id 8787477Conference paper (Refereed)
    Abstract [en]

    Patients with Parkinson disease (PD) exhibit a gait disorder called festinating gait which is caused by deficiency of dopamine in the basal ganglia. To analyze gait of patients with PD, different spatiotemporal parameters such as stride length, cadence, and walking speed should be calculated. This paper aims to present a method to extract useful information represented by the positions of certain landmarks on the human body that can be used for analysis of PD patients’ gait. This method is tested using 132 videos collected from 7 PD patients and 7 healthy controls. The positions of 4 body landmarks, namely body’s center of gravity (COG), the position of the head, and the position of the feet, was computed using a total of more than 41000 of video frames. Results of object’s movement plots show high level of accuracy in the calculation of the body landmarks.

  • 299.
    Fleyeh, Hasan
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Yella, Siril
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Hansson, Karl
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Feature selection and bleach time modelling of paper pulp using tree based learners2016In: Web Information Systems Engineering – WISE 2016: 17th International Conference, Shanghai, China, November 8-10, 2016, Proceedings, Part I / [ed] Wojciech CellaryMohamed F. MokbelJianmin WangHua WangRui ZhouYanchun Zhang, China - Shanghai: Springer, 2016, Vol. 10042, p. 385-396Conference paper (Refereed)
    Abstract [en]

    Paper manufacturing is energy demanding and improvedmodelling of the pulp bleach process is the main non-invasive means ofreducing energy costs. In this paper, time it takes to bleach paper pulpto desired brightness is examined. The model currently used is analysedand benchmarked against two machine learning models (Random Forestand TreeBoost). Results suggests that the current model can be super-seded by the machine learning models and it does not use the optimalcompact subset of features. Despite the differences between the machinelearning models, a feature ranking correlation has been observed for thenew models. One novel, yet unused, feature that both machine learningmodels found to be important is the concentration of bleach agent.

  • 300.
    Folmerz, Mattias
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Oljeläckage torkparti PM12: Utvärdering av oljeläckage i torkparti PM122017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Stora Enso Kvarnsveden is a paper mill located at Dalälven in Kvarnsveden. The utility currently has two producing machines, and this study deals with one of them, which is PM12. At PM12 there is a problem with oil leaks in the machine's drying section. Leakage occurs through the bearing houses who are there to support the dryer's rollers. In this study, it has been investigated what the leakage is due to focusing on its bearing seals.

    The purpose of this study has been to investigate why leakage occurs and to generate concepts to reduce or eliminate leaks. The study has included various measurements and investigations to address the problem. A literature study has been conducted to identify causes and solutions. Concepts have been generated from the literature study as well as the measurements that have been taken.

    After this study it´s not fully realized why the leakage occurs, but it had come a long bit on the way. Proposals for continued work have been given, where it is recommended more specifically what kind of measurements that should be done and the concepts that should be further developed.

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