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  • Lehtinen, Tuomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Internal Combustion of an Asteroid Recorded Using a Spacecraft (ICARUS): Mission Definition Review2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Savci, Mattias
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Mervärdesskatt: Ekonomisk brottslighet inom EU2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Inom den Europeiska unionen har vi idag principen om den fria och gemensamma marknaden där moms ska tas ut i det land där varan konsumeras. Detta innebär att företag inom unionen kan handla varor momsfritt. Det var år 1993 som man inom unionen avskaffade momstullen, vilket i sin tur ledde till att det blev svårare att kontrollera momssystemet. Brottsligheten och bedrägerierna ökade i samband med avskaffandet av tullarna och skattekontrollen blev betydligt sämre då man inte längre betalade momsen vid tillförandet. Detta öppnade för bedrägerier såsom ökad karusellhandel, fiktiv handel- och penningtvätt. Det medför stora kostnader för staterna som utsätts för bedrägeri i form av moms. Med hjälp av den rättsdogmatiska metoden har det i uppsatsen redogjorts för gällanderätt avseende den ekonomiska brottsligheten för att avslutningsvis komma fram till ett förslag till lösning på det aktuella problemet. Ett förslag när det gäller momskarusell är att det inte ska förekomma moms vid handel av två företag inom landet, utan att de företag som säljer till slutkonsument istället ska påföra moms.  

  • Swain, Adyasha
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Catalyst: A Cloud-based Data Catalog System for a Swedish Mining Company2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In today’s digitization scenario, drivers such as the Internet of Things (IoT), cloud computing and big data lead to many initiatives such as Industry 4.0 or smart manufacturing. Large mining organizations are witnessing the emergence of big data not only through IoT but also through legacy systems and internal processes. Addressing big data is a challenging and time-demanding task that requires an extensive computational infrastructure to ensure successful data processing and analysis. Though most organizations have adopted a wide variety of powerful analytics, visualization tools, and storage options, efficient data usage, and sharing is taxing and may lead to data isolation. The thesis proposes, develops and validates a data catalog system called CATALYST: A Cloud-Based Data Catalog System for a Swedish Mining Company to address the data isolation, access and sharing challenges faced in a large organization. The prototype implementation and the evaluation of our system show that the average query time  was  reduced  from  59.813  milliseconds  to  11.009  milliseconds, as well as the average data count was reduced from 12,691 to 5721.7, which is almost less than 50 per cent, and solving data isolation challenges within Boliden, a large Swedish mining company. Finally, Boliden has confirmed the value of CATALYST in general and finds it beneficial for data management within their organization

  • Xie, Qiancheng
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Yang, James
    Concrete Structures, Royal Institute of Technology; Vattenfall AB, R&D Hydraulic Laboratory.
    Lundström, T. Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Perturbation Theory and Sediment Carrying Capacity of Suspended Load in a Tidal River2019Conference paper (Refereed)
  • Al-Madhlom, Qais
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. University of Babylon, Babylon, Iraq.
    Hamza, B.
    University of Babylon, Babylon, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Laue, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nordell, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Hussain, Hussain M.
    Kufa University, Kufa, Iraq.
    Site Selection Criteria of UTES Systems in Hot Climate2019In: Proceedings of the XVII ECSMGE-2019: Geotechnical Engineering foundation of the future, Iceland: The Icelandic Geotechnical Society (IGS) , 2019, Vol. 1, p. 1-8Conference paper (Refereed)
    Abstract [en]

    Underground Thermal Energy Storage UTES systems are widely used around the world. The reason is that UTES is essential in utilizing Renewable Energy sources (RE). The efficiency of the energy system relies strongly on the efficiency of the storage system. Therefore, in the installation of a hyper-energy system, a lot of attention is to be paid in improving the storage system. In order to design an efficient storage system, firstly, standard criteria are to be investigated. These explain the process of making high efficiency storage system that must be specified. The criteria, mainly, depends on: best type and best location. These two variables are in high interference with each other. The bond between the two variables is represented by the geological, hydrological, meteorological, soil, hydrogeological properties/factors of the site. These factors are specified by geo-energy mapping. Despite the importance of this type of mapping, there is no specific criteria/formula that defines the choice. This paper aims to: give a brief literature review for UTES systems (types, classification, advantages/disadvantages for each type, and examples of an installed system). In addition, some factors within geo-energy mapping are highlighted and standard criteria to achieve good storage system are suggested. The suggested criterion comprises a process to transfer the quantity values to quality values according to the expert opinion. The suggested criteria are defined through the following stages: selecting the best type of UTES systems according to hydro-geological in site conditions; using the analytical hierarchy process to rank the best location to install the storage system and then using ArcMap (GIS-Software) to provide representative results as maps. Karbala Province (Iraq) is the study area used here

  • Abdullah, Twana
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Groundwater Directorate of Sulaimani, Kurdistan Region, NE, Iraq..
    Ali, Salahalddin
    Department of Geology, University of Sulaimani, Kurdistan Region, NE, Iraq.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering. Komar University of Science and Technology, Sulaimani, Iraqi Kurdistan Region, Iraq.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Assessment of groundwater vulnerability to pollution using two different vulnerability models in Halabja-Saidsadiq Basin, Iraq2020In: Groundwater for Sustainable Development, ISSN 2352-801X, Vol. 10, article id 100276Article in journal (Refereed)
    Abstract [en]

    Groundwater aquifer in Halabja-Saidsadiq Basin considered as one of the most important aquifers in terms of water supplying in Kurdistan Region, NE of Iraq. The growing of economics, irrigation and agricultural activities inside the basin makes it of the main essentials to the region. Therefore, pollution of groundwater is of specific worry as groundwater resources are the principal source of water for drinking, agriculture, irrigation and industrial activities. Thus, the best and practical arrangement is to keep the pollution of groundwater through. The current study aims to evaluate of the vulnerability of groundwater aquifers of the study area. Two models were applied, to be specific VLDA and COP to develop maps of groundwater vulnerability for contamination. The VLDA model classified the area into four classes of vulnerability: low, moderate, high and very high with coverage area of (2%,44%,53% and 1%), respectively. While four vulnerability classes were accomplished dependent on COP model including very low, low, moderate and high vulnerability classes with coverage areas of (1%, 37%, 2% and 60%) respectively. To confirm the suitability of each map for assessment of groundwater vulnerability in the area, it required to be validated of the theoretical sympathetic of current hydrogeological conditions. In this study, groundwater age evaluated utilizing tritium isotopes investigation and applied it to validate the vulnerability results. Based on this validation, the outcome exhibits that the vulnerability classes acquired utilizing VLDA model are more predictable contrasted with the COP model.

  • Chapman, David
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Larsson, Agneta
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Toward an Integrated Model for Soft-Mobility2019In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 16, no 19, article id 3669Article in journal (Refereed)
    Abstract [en]

    A key urban design challenge is to create built environments that encourage outdoor activityall year round. This study explores a new model for soft-mobility that places the interaction betweenthe urban form, the seasonal climate and climate change, and the individual at the center of people’ssoft-mobility choices, or in more general, their modal choice. The research methods used werecomparative studies of documents, surveys, mental mapping, and photo elicitation. These studieswere undertaken to research people’s outdoor activity in the built environment during the winterseason of a cold climate settlement. The results were analyzed against the three-dimensions of themodel. In the discussion it is argued that in places with significant climate variation, the interactionbetween the urban form, the season, and the individual together influence soft-mobility choices. Inturn, these interactions influence people’s level of outdoor activity and the individual health benefitssuch activity can aord. In conclusion, it is highlighted that all three dimensions of the model are in aconstant state of change and evolution, especially in relation to planning and development processesand climate change.

  • Lundbäck, Maria
    Luleå University of Technology, Department of Arts, Communication and Education.
    Distansbaserad grund- och gymnasial vuxenutbildning: De studerandes upplevelse av stöd, inkludering och relationer2019Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this study, the aim has been to examine students with earlier school failure, their experience of studying primary and secondary courses on municipal adult education and distance learning. In 2018, the Ministry of Education published a report about municipal adult education (SOU 2018:71) which showed that there is an altered group in adult education that contains more immigrants and people in need of support to manage school. The focus in this study has been on examining the students experience and inclusion, support and the relation to their teachers. The aim came from the fact that there are many students that leave upper secondary school without grades and many of them apply for adult education. This study contains interviews with four students with many missing points for a high school degree. It also includes literature review in areas of inclusion, distance studies, support, neuropsychiatric disabilities and Sense of Coherence. The results show that distance studies are a good alternative form of studying for the students in this study, with school failure, but that they all need a lot of quick feedback and support, in various forms. They also need good relations too the teachers in order to manage distance studies. The informants in this study are positive to study at municipal adult education and distance, if they get the right support.

  • Talvistu, Siiri
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    EM emissions test platform implementationfor satellite electric propulsion systems andelectronic subsystems2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Modern gridded ion thrusters for CubeSats operate by generating high power and canpose challenging problems with Electromagnetic Interference (EMI). In order to verifycompatibility with neighbouring equipment, strict standards such as the militarystandard MIL-STD-461G, are required to be followed to achieve ElectromagneticCompatibility (EMC). To avoid abrupt and cataclysmic delays in production time, incase the product fails to comply with the requirements, companies integrate in-housepre-compliance tests into their development phase. The objective is to implementin-house measurement methods on an electric propulsion model NPT30 developedby ThrustMe. This document explains the process and methods to perform conductedemission test on power lines and radiated emission tests in the magneticfield. A custom measurement system integrity verification was developed for theradiated emission test. The presented results provide the engineers at ThrustMe aninsight on the electromagnetic behaviour on the ion thruster NPT30 and whethermodifications need to be included in the next development iteration to mitigate forthe detected excessive emission levels. When EMC methods are implemented earlyon in the development process, there are more pre-emptive mitigation options withless costs in time and money. By performing in-house pre-compliance tests andtaking measures to prepare for the tests at a certified EMC test house, the companycan be more confident in their product at passing the EMC tests. Based on the twoperformed in-house tests, the engineers at ThrustMe began to include mitigationmethods in the following circuit design iterations.

  • Abdul-Jalbar, Beatriz
    et al.
    Dpto. de Matemáticas, Estadística e Investigación Operativa, Universidad de La Laguna, Spain.
    Segerstedt, Anders
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    A note on “A new heuristic for one warehouse and N retailers problem” by Ercan Senyigit and Hakan Akkan in Procedia - Social and Behavioral Sciences, 62, p. 656 – 660, 20122019Manuscript (preprint) (Other academic)
  • Fallahjoybari, Nima
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Lundström, Staffan T.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    A Subgrid-Scale Model for Turbulent Flow in Porous Media2019In: Transport in Porous Media, ISSN 0169-3913, E-ISSN 1573-1634, Vol. 129, no 3, p. 619-632Article in journal (Refereed)
    Abstract [en]

    Given the analogy between the filtered equations of large eddy simulation and volume-averaged Navier–Stokes equations in porous media, a subgrid-scale model is presented to account for the residual stresses within the porous medium. The proposed model is based on the kinetic energy balance of the filtered velocity field within a pore; hence, when using the model, numerical simulations of the turbulent flow in the pores are not required. The accuracy of the model is validated with available data in the literature on turbulent flow through packed beds and staggered arrangement of square cylinders. The validation yields that the model successfully captures the effect of the pore-scale turbulent motion. The model is then used to study turbulent flow in a wall-bounded porous media to assess its accuracy.

  • Girardello, Carlo
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Optical Analysis of Plasma: Flame Emission in Cryogenic Rocket Engines2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis contains the results of optical flame emission measurements of the Vulcain 2.1engine and the plasma emission spectroscopy of the Lumen Project engine. The plume spectroscopyis analyzed, ordered and studied in detail to offer the best possible molecular composition.The main focus relied on the hydroxide radical, blue radiation and other moleculesanalysis of the intensities encountered during the tests. The plasma emission spectroscopy isfocused on the determination of the plasma temperature value in LIBS measurements. Thehydrogen plasma temperature determination of the local thermodynamic equilibrium, followedby the carbon and sequentially oxygen plasma is obtained. The quality of the LTE isto be determined to judge the truthworthness of the determined temperatures. Both the testsare analyzed thanks to the use of spectrographs, cameras and dedicated software for opticalapplications. The results related to the Vulcain 2.1 LOX/LH2 engine showed the evolutionof the plume in different ROF or pressure variations. Furthermore, the results of the LumenProject LOX/methane engine led to the determination of the plasma temperatures and a firstestimation of the LTE quality.

  • Wikman, Kasper
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Integration of Orbital Control in the Avionic Test-Bench Simulators for EagleEye: Evolution of the EagleEye functionality2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the space industry a lot of efforts is put towards verification and validationof the different parts of the spacecraft. This is a costly process and cause initial friction when trying to introduce new technology within the field. One of the demanding systems to validate and test is the on-board software. To makethe process of evaluation and testing of new technologies easier, the EuropeanSpace Agency has put effort towards creating an end-to-end avionic test bench containing four different simulators. In this test bench a fictional mission called EagleEye was constructed. EagleEye is a representative low-cost & low-powerEarth observation mission to create a fictive environment to perform system tests.

    As of 2018 the mission still lacked the functionality of orbital maintenance. However, during the autumn of 2018 the system had the orbital control modeintroduced to the Functional Engineering Simulator in the MATLAB Simulink environment.This was one process for the integration of the orbital control mode, thesystem still had three additional simulator environments requiring the implementation: Functional Validation Test-Bench, Software Validation Facility andReal-Time Test-Bench. This thesis covers the implementation within the first two simulators mentioned. The work was carried out during the spring of 2019 and showed that the simulators were updated successfully and verified. Development of the simulator will continue as there are still things to be done.

  • Eriksson, Mattias
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Selektivplan SCA Bionorr2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report presents a project in SCA Graphic Sundsvall AB's with purpose to establish setting values for the protection relays, to achieve selectivity in the plant. The problem with the plant is that the protection relays trigger higher up in the power grid, which result in shutting down a large area of the production instead of triggering the protection relay closest to the fault. This problem may be a result of that the plant have experienced several upgrades and developments over many years, and that the loads in the plant's power grid also been changed, but the protection settings have not been adjusted to the new circumstances.

     

    A protection relay monitors parts of an electrical power system to detect when the pre-set limit values are exceeded. If a fault occurs, surpassing of those limit values enables the protection relay to send a signal to a circuit breaker to open and isolate the faulty components. The protection relays can provide many different types of protection. In this project the following are considered; overload protection, overcurrent protection, and earth fault protection.

     

    The equations used in this report are based on a constant time perspective as a base, which means that a fixed time difference is set between the tripping times of protection relays, which is independent of the function value. Microsoft Excel is used to perform the calculations. To make it easier for the reader of the report to understand how the equations in the report are used, one example of the calculations made for one of the lines is shown.

     

    The calculated results of the setting values for the protection relay and power switches that were requested by SCA are presented in tables. Since few values were provided regarding the previous setting values, it is difficult to compare the previous setting values with the proposed ones. Also, the ratio of the current transformers from previous setting values was unknown, where different sources showed different ratios. However, setting values were determined for both possible ratios for each protection relay, allowing the company to set the protection correctly, once they find the right ratio.

     

    Based on the calculations, the time settings should be changed, so that they trigger in selective order, but also that the current settings values should be set to the new values based on the plant's present components and operating mode.

  • Eriksson, Michaela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Utvärdering av byggprojekts tillämpning av Lean Construction i produktionen: framtagning av en mognadsmodell2019Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    In comparison to the manufacturing industry, with companies such as Toyota in the lead, the construction industries attempt to increase productivity has remained low for the past 40 years. The manufacturing industry has achieved great results by working with Lean Production. Lean at is core is about minimise waste and maximise value. Waste comes in many forms, and one definition is the eight wastes of Lean: overproduction, waiting, transportation, extra processing, inventory, motion, defects and non-utilized talent. The objective with the master thesis was to develop a maturity model that evaluate construction sites involvement with Lean Construction based on the eight wastes of Lean, and that it should be possible to use the model as a template for improvements.

    The master thesis, which foremost has a qualitative research strategy, is an exploratory study that has answered on how construction sites can be assessed by Lean with the base of the eight wastes of Lean. The research approach is deductive since the maturity model has been devel- oped by using existing theory in order to assess construction sites in real situations. To ensure validity a work procedure by triangulation has been used. The supervisors reviewing the work has also contributed to the validity. The reliability has been sought by documentation and con- tact with supervisors continuously.

    The maturity model consists of 20 categories that in different ways has a base in the eight wastes of Lean. These categories are assessed by a level scale 1-5, where level one is the lowest im- plementation, and level five is the highest implementation. The results from the assessments showed that there are differences between the construction sites even though they are performed by the same company, and that there is potential for improvements.

    The analysis suggests that the majority of the categories need some sort of modification. Mainly by sectioning some categories into two or more categories, or reformulation of categories that did not work based on reality that appeared during the site visits. It also appeared that some categories overlapped each other, and that it was hard remembering all the categories with its descriptions when testing the model. This imply that the model should be more compact and less limiting. The maturity model was also analysed by an analysis model to investigate when a maturity model like the one that has been developed could be used.

    The master thesis would have improved if it had been performed with a co-writer since a qual- itative study like this result in subjectivity which had been more objective if there would have been two perspective. The base for the maturity model which was the eight wastes of Lean is considered, now afterwards, to be a little too narrow since there is other areas in Lean Con- struction which are considered to be important, such as security. If the maturity model would have been tested before the primary assessments it could have been realised and thereby mod- ified before the site visits. More development and research have to be done after this thesis is presented.

    There are five focus areas which should be included in a maturity model in order to assess the application of Lean Construction, these could be divided into several categories as long as they aren’t too extensive. The result shows that there is a difference between the investigated build- ing productions in four categories, but the reason behind this is unknown. The maturity model has been developed in such a way that it can be used in the improvement work and the devel- opment of the application of Lean Construction.

  • Johansson, André
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Ericsson, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Brottsannolikhetsberäkningar knutna till snölaster: Uppskattning av snölaster med en återkomsttid på 50 år och analys av spatiala interpolationsmetoder för att utforma framtida snölastkartor2019Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [sv]

    Under konstruktionsskedet av byggnader beräknas bland mycket annat permanent och variabel last. Permanent last är som namnet antyder last från delar av konstruktionen som ständigt är närvarande, till exempel egentyngd. Variabel last är av mer skiftabde art och kan till exempel bestå av omgivande klimatologiska påverkan, så som vind och snö. Snölasten på en byggnad uppskattas genom att utgå från snölast på mark som, beroende på byggnadens utformning, beräknas till snölast på tak. Genom att statistiskt beräkna 50-årssnölasten på mark för given geografisk plats går det genom vidare kalkyleringar att konstruera en byggnad med önskad brottsannolikhet. I detta arbete har, med hjälp av insamlad snödjupsdata från mätstationer i Sverige under perioden 1961-2015 beräkna snölastens grundvärde på mark för en återkomsttid på 50 år beräknats. Detta har gjorts med hjälp av fyra statistiska fördelningsfunktioner, gumbel, weibull, lognormal och GEV. De statistiska beräkningarna utfördes med hjälp av Matlab. Ett vilkor var att varje mätstation måste ha minst 35 stycken registrerade säsonger för att inte sorteras bort. Vidare utvärderades varje fördelning mot mätvärdena med ett Anderson-darling- och Lilliefors-test samt jämfördes inbördes med Akaike information criterion. Ur uppskattat 50-årssnödjup för de specificerade fördelningsfunktionerna ovan har en snölast beräknats utifrån tidigare uppskattad snödensitet. Genom att tillämpa interpolationsmetoderna inverse distance weighting (IDW) och ordinär kriging har rikstäckande snölastkartor för varje fördelning skapats. Dessa jämfördes sedan mot snölastkartan Boverkets konstruktionsregler EKS. Det visade sig att varje fördelning ger varierande resultat och att det generellt sett är svårt att dra slutsatser om vilken fördelning som passar bäst. Problematiken med att dela in Sverige i snölastzoner där beräknat resultat förenklas och underrespektive överskattar snölasterna beroende på vilken sida av snölastzonerna byggnaden är placerad har också undersökts genom att göra brottsannolikhetsberäkningar. Detta utifrån ett exempel med en 10 meter lång fritt upplagd balk av konstruktionsvirke med en jämt utbredd dimensionerande last på 10 kN/m. Lasterna som simulerades är permanent last som beskrivs av en normalfördelning med en variationskoefficient på 5% samt en variabel last som beskrivs av en gumbelfördelning med en variationskoefficient på 40%. Bärförmågan av balken beskrivs av en lognormalfördelning med en variationskoefficient på 15%. Brottsannolikheten beräknades för Boverkets tre säkerhetsklasser. För en konstruktion som dimensioneras i säkerhetsklass 1 är brottsannolikheten per år, statistiskt sett en på tio tusen. I säkerhetsklass 2 är brottsannolikheten per år en på hundra tusen och säkerhetsklass 3, en på en miljon. Förhållandet mellan den permanenta och den variabla lasten varierades i laststeg om 0,25 kN/m. I det första simuleringsfallet var den permanenta lasten 10 kN/m och den variable 0 kN/m. I det sista simuleringsfallet var den permanenta lasten 0 kN/m och den variabla 10 kN/m. Varje lastfall simulerades 50 miljoner gånger. Snözonernas gränser är ritade vid medelvärdet av två närliggande stationer. Det innebär exempelvis att gränsen mellan snözon 1,0 och 1,5 är ritad vid 1,25 𝑘𝑁/𝑚ଶ . Detta medför att den faktiska brottsannolikheten är högre än vad den bör vara för en station som ligger i snözon 1,0 men nära gränsen till 1,5. För att beräkna vad den faktiska brottsannolikheten är vid gränserna ökades den karakteristiska variabla lasten med 0,25 𝑘𝑁/𝑚 utan att reducera den permanenta iii lasten. Detta innebär att det första simuleringsfallet simulerades med en variabel last på 0,25 kN/m och en permanent last på 10,0 kN/m. Det visade sig att brottsannolikheten för simuleringsfallet med dagens snözonskarta stämmer väl med den förväntade brottsannolikheten när den variabla lasten är mindre än cirka 60% i simuleringsfallet. När den karakteristiska snölasten ökades med 0,25 kN/m, utan att minska den permanenta lasten, ökade brottfrekvensen men påverkade inte brottsannolikheten nämnvärt så länge den variabla lasten fortfarande är mindre än cirka 60%.

  • Öhlund, Denice
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Närståendetransaktioner i aktiebolag: En utredning av hur närståendetransaktioner rättsligt hanteras2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den reglering som finns för aktiebolag är omfattande men saknar vid denna studie en uttrycklig reglering för närståendetransaktioner. Syftet med studien har därför varit att utreda området närståendetransaktioner och hur företeelsen rättsligt hanteras. För att uppfylla syftet med studien har rättsdogmatisk metod använts. Närståendetransaktioner kan efter denna utredning framställas innebära överföringar eller överlåtelser av tillgångar eller komponenter mellan ett aktiebolag och närstående till aktiebolaget. Utredningen visar även att närståendebegreppet anses vara i behov av en avgränsning och generalisering eftersom den krets av personer som omfattas av närståendebegreppet varierar mellan olika bestämmelser. Vidare visar utredningen att det finns betydande reglering som rättsligt hanterar närståendetransaktioner. Sådan reglering finns exempelvis i aktiemarknadsnämndens uttalande AMN 2012:05, aktiebolagslagens 17 kap. ABL om värdeöverföringar och 16 kap. ABL om riktade emissioner. Rättspraxis har även visat att dessa bestämmelser rättsligt kan hantera närståendetransaktioner i praktiken, däremot ger rättspraxis ingen sammantagen vägledning för hur närståendetransaktioner praktiskt ska bedömas utan uppfattas bedömas i varje enskilt fall.

  • Sabourova, Natalia
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Grip, Niklas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Tu, Yongming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Southeast University, Nanjing, China.
    Wang, Chao
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Southeast University, Nanjing, China.
    Enochsson, Ola
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Boden Kommun.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Nilsson, Martin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Railway Concrete Arch Bridge over Kalix River at Långforsen: Dynamic Properties and Load-Carrying Capacity2019Report (Refereed)
    Abstract [en]

    The concrete arch bridge over Kalix River at Långforsen was built in 1960 and has a mid-span of 89,5 m and a height of 13,7 m. The bridge owner, Trafikverket, wanted to increase its allowable axle load from 225 to 300 kN. Field tests were carried out under service condition and with ambient vibrations. The test results were used to update and validate Finite Element Models. At last, the refined models were used to check the possibility to increase the axle load.

    According to earlier assessments, most parts of the bridge is capable of carrying an axle load of 330 kN. The only critical sections are located in the beams carrying the rail on top of the arch in the section where the beams are united with the arch. Here the stresses in the longitudinal bottom reinforcement are slightly too high.

    These sections have been studied in a FEM model for different loads and results show maximum strains of about 50·10-6 corresponding to stresses of only about 10 MPa in the reinforcement in the critical sections. Live load vertical deflections of the crown of the arch is of the order of only ± 6 mm. Dynamic studies have also been made showing that fatigue is no issue. Altogether the studies show that the bridge is able to carry an increased axle load of 300 kN without problems.

  • Baños García, Adrián
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Use of precise point positioning techniques in GNSS applications2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Delehag Lundmark, Joel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Photogrammetry for health monitoring of bridges: Using point clouds for deflection measurements and as-built BIM modelling2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Road and railway bridges play a crucial role for the infrastructure network in Sweden to work smoothly and keep the traffic flowing. Damage to a bridge can have catastrophic consequences if they are not corrected properly and in due time. Trafikverket in Sweden is responsible for inspection and maintenance of approximately 20 600 bridges throughout the country. This huge number of bridges require large resources in the form of machinery and experienced bridge inspectors who assess the state of the bridges on the spot. At present, the state of a bridge is to a large extent determined by a visual inspection and by manually taking measurements to assess the condition of the bridge. This approach means that the assessment of the condition of the bridge to a large extent is subjective and shifting between different cases depending on the inspector’s experience. New approaches that both could make it easier for inspectors to make more objective decisions and facilitate and reduce the risk concerning the inspection work are therefore under research. In this thesis Close Range Photogrammetry is evaluated as a mean for assessing deflection on concrete bridges and for creating as-built BIM:s for documentation and visualization of the actual condition of a bridge. To evaluate the technique both laboratory experiments and field work are conducted. Laboratory tests are conducted on concrete slabs that are subjected to pressure to inflict deflection on them. The concrete slabs are photographed using close range photogrammetric techniques for different values of deflection. The photographs are later processed into a point cloud in which measurements of deflection are taken and compared to what is measured using displacement transducers during the tests. The field work conducted is in form of photographing a railway bridge using close range photogrammetry and building a point cloud out of the photographs. This point cloud is then used as a basis for evaluating the process on how a point cloud generated through close range photogrammetry can be used to create as-built Building Information Models. Results from the laboratory experiments show that changes in deflection can be visualized by overlapping point clouds generated at different loading stages using the software Cloud Compare. The distance i.e. the deflection can then be measured in the software. The point cloud generated through the field work resulted in a as-built BIM of the railway bridge containing the basic elements. No hard conclusions can be drawn as to how well the method in this thesis can be used to measure deflection on real concrete bridges. The test basis is to small and the human factor can have affected the results. The results though show that millimeter distances can be measured in the point clouds which indicates that with the right approach, Close Range Photogrammetry can be used to measure deflections with good precision. Point clouds generated through Close Range Photogrammetry works good as a basis for creating as-built BIM:s. The colored point cloud is beneficial over other techniques that are generated in gray scale because it makes it easier to distinguish elements from each other and to detect any deficiencies. To create complete as-built BIM:s more than just a point cloud are needed as it only visualizes the shell of the captured object.

  • Huang, Mingjiao
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Metoder för inventering av väg: Vid Ramböll Sverige AB2019Independent thesis Basic level (university diploma), 80 credits / 120 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete har utförts på uppdrag av Ramböll RST i Luleå. Syftet har varit att beskriva metod och process för arbetet med väginventering. Det har lagts särskild vikt vid att beskriva för- och nackdelar med nuvarande metoder. Syftet med inventering är att klargöra det fysiska och funktionella tillståndet hos vägen och dess sidoområde. Inventering är underlag för planering och genomförande av åtgärder som erfordras för att säkerställa att kraven uppfylls på både kort och lång sikt. Inventeringen avser att identifiera homogena delsträckor för att möjliggöra projektering av lämplig åtgärd. (VVMB120 Inventering och värdering av befintlig väg, 2009) RST avdelning på Ramböll erbjuder en underhållsutredning som redovisar en detaljerad bild av tillståndet på gator, vägar och GC-nät. Resultatet ger politiker och tjänstemän ett viktigt underlag i budgetarbetet. Underhållsutredningen gör att insatserna kan optimeras för att ge största effekt och bästa funktion per satsad skattekrona. Företaget har som målsättning att deras metoder för inventering ska vara ledande i Sverige. Arbetet med inventering kan utföras ekonomiskt och effektivt med aktuella metoder, men det finns begränsningar hos nuvarande metoder som påverkar arbetets kvalitet. I detta examensarbete har jag behandlat:  Processen för arbete med inventering  Vad innebär arbetet med inventering  Vilka metoder har Ramböll RST för att utföra inventering I rapporten utreds för- och nackdelar med de aktuella metoderna. Det finns även en diskussion om hur inventeringen kan göras på kortare tid och ändå bevara hög kvalitet. Min förhoppning är att denna rapport kan vara underlag för en positiv utveckling av arbetet.

  • Lindh, Daniel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Bergström, Jens
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Design of a Coprocessor Board for an On Board Computer2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The goal of this thesis is to design a coprocessor expansion board for an On Board Computer (OBC) using Commersial Off The Shelf (COTS) components. This is done in order to meet the increasing demand of more processing power as spacecrafts become more autonomous. After evaluating a number of different options, the LS1046A from ARM was chosen as the processing unit. This would increase the processing power from the current 110 Dhrystone Million Instructions Per Second (DMIPS) to a theoretical 22 560 DMIPS. The schematic was designed in DxDesigner, and after the layout was completed signal integrity simulations were performed in HyperLynx. After modifications to termination resistances, the simulations showed good signal integrity confirming proper routing of the signals. After receiving the manufactured Printed Circuit Board (PCB) with all components mounted, some tests could be performed confirming that the power distribution and the system clock was functioning properly.

  • Nordmark, Alina
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Läroplanens styrande effekt: En studie om Lgr11 och dess styrande effekt över lärarkåren2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studiens syfte är att undersöka vilken styrande effekt Lgr11 har i lärares yrkesutövande, meningen med undersökningen är att få en insyn i om hur de professionella lärarna upplever att de är påverkade av läroplanen i deras yrkesutövning. Studien har sin teoretiska utgångspunkt i Michael Lipskys teori om närbyråkrater och deras handlingsutrymme samt Lennart Lundquist´s teori som handlar om hur närbyråkraterna förstår, kan och vill i en implementeringsprocess av exempelvis en läroplan. Huruvida närbyråkraterna- i detta fall lärarna- förstår, kan och vill är viktigt att studera eftersom att det är avgörande för om styrningen lyckas eller inte. En analysmodell har utformats utifrån Lundquist´s teori och de tre centrala begreppen. Den metod som använts är samtalsintervjuer med fyra grundskollärare från två olika skolor i Luleå kommun. Detta dokumenterades med ljudinspelning som sedan transkriberades kontinuerligt efter varje intervju. Analysmodellen användes när intervjuerna sammanställdes och resultatet som visas är att det finns många olika åsikter bland lärarna gällande exempelvis Lgr11:s formulering. Resurser och Lgr:11s mål och värderingar är däremot saker som alla lärare var överens om. Intervjuerna och studien har lett till en djupare förståelse för lärarnas syn på läroplanens styrning på de skolorna som är med i undersökningen.

  • Sehlin, Olov
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Genetic algorithm tuning of artificial pancreas MPC with individualized models2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Diabetes is a growing chronic disease and a worldwide problem. Without any available cure in sight for the public other methods needs to be applied to increase the life quality of diabetic patients. Artificial Pancreas (AP), a concept of having a closed loop system to control the glucose level on Type 1 Diabetes (T1D) patients has been introduced and is under development. In this thesis, Model Predictive Control (MPC) has been re implemented from scratch in MATLAB/SIMULINK with associated Kalman filter and prediction function. It was implemented in the latest version of the UVA/Padova Simulator which is a tool approved by FDA for simulating diabetes treatment in order to speed up the AP development. Different MPC cost functions where tested together with integral action on a simplified system using a linear approximation of a population model. It was implemented and tuned with a new simulation tuning method using Genetic Algorithm (GA). It showed that the quadratic cost function without integral action was the best with respect to performance and time efficiency. 3 hours was the best prediction horizon and was used for the individualized tuning using the University of Virginia (UVA)/Padova simulator. For the individualized MPC, models identified by the University of Padova were used. These simulations showed that an individualized model could be used for improved T1D treatment compared to an average population model even though the results were mixed. Almost all of the patients got improved treatment with the closed treatment and non hypoglycemic event occurred. The identification of better models is a great challenge for the future development of the AP MPC due to the excitation problems.

  • Zetterström, Sebastian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Utvärdering av brandtekniska egenskaper för självbindande bokfaner: Baserat på tester i konkalorimeter2019Independent thesis Basic level (professional degree), 210 HE creditsStudent thesis
    Abstract [en]

    Abstract

    This study describes an attempt to determine and evaluate the thermal properties of self-bonding beech veneer. These properties mainly consist of time to ignition and rate of heat release. The determination was done by performing bench-scale trials in a cone calorimeter. The material studied consists of three different sets of self-bonding veneer boards, which have bonded without any additives. The technology for making the boards is developed by Carmen Cristescu. Making the boards involves constant compression under a constant period of time, while allowing a variation in temperature. This results in different characteristics of the final product, such as higher adhesion capabilities between the veneer layers, when the temperature is raised to 250°C.

    Time to ignition have been measured and compared with hand calculations. All collected data from the experiment and the hand calculations have also been compared to related products, such as plywood and LVL.

    The study indicates minor differences between the mutual beech veneers, or for example ordinary plywood, regarding the studied characteristics. Observations during the tests indicate that the interconnecting properties vary between the boards when they are subjected to higher temperature. As the study show similar rate of heat release such as plywood, it is reasonable to assume that the same application range can be recommended.

    Due to the different density 745, 823 and 1045 kg/m3 developed while making the boards and for the further simplicity of the report the boards are henceforth called low, medium and high density boards.