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  • 151.
    Andersson, Tomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Optimering av balkonglösning2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This dissertation describes the theory behind a specific solution for balcony attachment for concrete constructions designed by Prefabmästarna. The purpose is to get a deeper understanding of design according to Eurocode and EKS (Swedish application of eurocode) and to optimize the current solution for balcony attachment in view of reduced material usage. The design is based on a prefabricated balcony slab is fasten to a T-section whose flanges are molded in a prefabricated DFS-slab. Two tie-rods is threaded into the balcony slab and fasten to the T-section with a washer. After mounting of the balcony slab the DFS slab is molded on which stabilizes the T-section from instabilites. The results show that the structure is largely optimized but that there are room for improvements in specific places. For balconies with a length of 2.0 meters the T-section can be reduced with 10 kg of steel, which corresponds to more than 50 % of the T-section weight compared with the reference solution. Also at the 2.5 meter balconies the T-section can be reduced with 7 kg of steel, which corresponds to a 38 % reduction in material use compared with the reference solution. A common standard for the T-section is possible for balconies with a length of 2.0 and 2.5 meters.

  • 152.
    Andersson, Victor
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Elektrifiering av personbilar på Tomtebo, Umeå: Electrifications of passenger cars at Tomtebo, Umeå2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the future, new fuels will be sought to minimize the carbon footprint on Earth. With electric vehicles becoming a growing trend there is an annual increase in hybrid and electric cars, even electrified buses have become more convenient. The new electric vehicles will then be a load on the electricity grid when recharging is required, sometimes during the sensitive hours of the day where other power requirements are greater. The purpose of this thesis was to gain a deeper understanding of how the Swedish electricity grid is structured and also answer the questions if the area named Tomtebo will be able to handle an electrification of passenger cars, and also what the power forecast will look like. An excel model, developed by Sweco, is used for the calculations and later on there is an evaluation of this model if it can be applied to smaller areas and if any improvements can be made towards it. The electric car load on the electricity grid is based on three possible scenarios referred from a report by Sweco and using the excel model to calculate the power requirement of the three scenarios with different traffic works on electricity. Scenario one corresponds to today's electrification degree on traffic work, scenario two corresponds to double electrification degree on traffic work and in scenario three, a full electrification as well as a new traffic hierarchy with more public transports will be used, according to the report by Sweco, resulting in less power requirements for traffic. In all three scenarios, it is assumed that the electric car will be charged at night with a charging power of 2.3 kW, this corresponds to charging directly from power outlet. Tomtebo is a residential area that is being expanded and is expected to grow in the coming years and the population there are mostly younger families, which gives the probability of investment of a fossil-free passenger car increase. In order to estimate the proportion of electric cars for the area, Statistics Sweden and Region facts have been used to estimate the amount of cars at Tomtebo. In Umeå there is a total of 1,400 electric cars and 95 of these were likely to be at Tomtebo. Out of this amount there is plugin hybrids, PHEV, and pure electric cars, BEV, which gave a distribution 75/25 percent according to data from national statistics. With a known number of cars, an itinerary was required which could be probable around twenty kilometers. In the Excel model, values were applied for scenario one, which gave the power requirement for the 95 cars a total of 18 kW per hour. With a grid that has a total power up to 3.7 MW per hour then the cars' power requirements are a minimal burden towards it, furthermore an equivalent result came from both scenarios two and three. With these three results came the conclusion that with the amount of cars available there today no major load was done on the electricity grid and thus a greater number of cars were required. Umeå aims to reach 200,000 inhabitants by the year of 2050, which would then give Tomtebo 12,000 residents and this would result in an estimated 6,100 cars there. Of these with today's distribution there would then be 200 electric cars but since this scenario is so far ahead in the future it was assumed that all vehicles in 2050 would be an electric car, which then leads to it being fully electrified at Tomtebo. The 6,100 electric cars power provided 6 MW of total power demand for today's electricity grid, which means that it won’t work in the future. To find the breaking point for how many electric cars the gird can handle it was assumed that all Tomtebo's cars today, corresponding to 3,780 cars, would be electric cars and by moving the charge schedule to early morning, when the demand was much lower, the result gave that the grid could handle about that many cars. What is important to understand is that the electricity grid does not have a maximum ceiling for demand, but it all works about equilibrium where one strives for a consistent power balance on all

    iv hours of the day. If the consumers need more power then the electricity companies transfer it but an under-dimensioned infrastructure can put a stop to this which might be the case in the future. When the question whether Tomtebo's electricity grid can handle the load, the answer is that a full electrification of Tomtebo is entirely possible but that future investments are something that should be reviewed. This result from the excel model using the parameters and assumptions reflects the reality. The difficult thing about using the model in my opinion is the estimation of car numbers where in a city like Umeå where there does not exist any cameras or registers of which car type is moving where, which it does on others places, such as Gothenburg and Stockholm. Furthermore, there are thoughts about the design of the model as well also the question of the depth of battery but this is left out here but can be read under the relevant section. What controls how quickly a changeover from fossil-fueled to non-fossil vehicles is the result of instruments where subsidies and taxation come into focus, then of course laws and regulations. What makes it so difficult to estimate what the future will look like in theory is that tomorrow can have a new law leaving only non-fossil vehicles.

  • 153.
    Andreas, Domeij
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering av en gammal kulturmärkt prästgård2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Reducing and improving the use of energy is something that is relevant in the current situation for both economic and environmental aspects. Energy goals have been set up to achieve a better and more efficient use of energy. This leads to buildings constructed as efficient as possible but it also involves existing buildings. This report investigates an old heritage rectory from the 1700’s that, with its high use of energy, will be analyzed and then simulated with a few measurements in the energy calculation program VIP Energy.

    The information about the rectory is limited. Many assumptions regarding the building’s construction and the occupants’ behavior were applied since documentation has been missing and since the building is currently empty. Svenska kyrkan is currently rebuilding the rectory since they intend to conduct business there in the future. A model was created in VIP with the goal to simulate the rectory when there still was activity in the building. The model were then simulated various measures that were additional insulation, renovation of windows and an installation of a FTX-system. The culture label has made measures that affect the façade, such as external insulation or replacing windows, disregarded.

    The results from the model showed that with all the measures together it is possible to reduce the specific use of energy of the rectory from 252 kWh/m

    2 to 111 kWh/m2 and thereby live up to the guidelines posted by The National Board of housing, Building and planning. Certain factors have deliberately been ignored such as moisture, due to time restrictions. The same thing applies to the economic part except for the ventilation where a lifecycle cost between a rotating heat exchanger and a plate heat exchanger has been compared to replace the existing exhaust system. The reason is that the ventilation is the most feasible solution for adaption to future use. LCC analysis showed a benefit to the rotary heat exchanger favor with a price difference for about 70 000 SEK towards the existing system, without installation costs or future reparations.

  • 154.
    Andreasson, Albin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konstant eller behovsstyrd ventilation i grundskolan: En jämförelse med hjälp av LCC-analyser2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Demand controlled ventilation is recognized as an option to constant air volume (CAV) ventilation. Capable of reducing the cost of energy usage, but having higher initial costs. This thesis investigates both these factors in order to see what gives the lowest LCC (life cycle cost).Using the case of a 1000 m2 primary school in Stockholm, Sweden, four different ventilation systems were analyzed: constant air volume (CAV) ventilation, CO2 controlled ventilation, CO2 and temperature controlled ventilation as well as occupancy controlled ventilation.All of the systems were constructed in the AutoCAD software, using the add-on MagiCAD. This made it possible to acquire detailed bills of materials that were exported to the accounting software Sektionsdata, which was used to calculate the initial costs of the systems down on a component level.The energy calculation software IDA ICE was used to perform simulations on both energy usage and indoor climate. Each system was simulated with three different sizes of occupancy.LCC was calculated for each system and occupancy using the net present value method, where CAV got the lowest with a wide margin. CO2 controlled ventilation got the second lowest LCC followed by CO2 and temperature controlled ventilation. Occupancy controlled ventilation got the highest LCC with a wide margin. This order did not depend on the size of the occupancy, but the LCC of the carbon dioxide controlled systems got smaller in comparison with the other systems when the occupancy was reduced.

  • 155.
    Andreasson, Simon
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Datainsamling röntgen2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 156.
    Anette, Nyström
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Undersökning av smarta energilösningar för en planerad livsmedelsbutik2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    På uppdrag av Hifab AB har detta examensarbete utförts under vårterminen 2015. En ny livsmedelsbutik ska etableras i Umeå, där Hifab AB har anlitats som generalkonsult av Coop Nord. I dagsläget finns endast ett utkast på hur byggnaden ska se ut eftersom byggnationen av butiken beräknas starta våren 2016. Detta innebär att det finns stora möjligheter att undersöka smarta energilösningar som kan appliceras på den framtida butiken. För att erhålla energistatistik att utgå från användes en Coop-butik i Kramfors som invigdes våren 2012 som referensbutik i detta projekt.

    Syftet med detta arbete var att undersöka olika energialternativ och energieffektiviserande byggtekniska lösningar för den planerade butiken. Detta för att den planerade Coop-butiken, tillsammans med andra framtida butiker, ska kunna byggas energieffektiv redan från början och för att driftkostnaden för butiken ska bli så låga som möjligt samtidigt som påverkan på miljön blir minimal. Detta projekt ska vara en vägledning i val av energisystem och byggtekniska lösningar för den aktuella Coop-butiken och även vid projektering av framtida livsmedelsbutiker i Sverige, framförallt i norra delen av landet.

    Projektet har innehållit två olika delar och ett flertal mål. Det första delmålet var att undersöka vilket av alternativen fjärrvärme eller bergvärme som är det mest ekonomiskt lönsamma för den nya butiken. Nästa delmål var att undersöka möjligheten och kostnaden för att installera solceller på den nya butiken. Målet var även att undersöka om det fanns alternativa sätt att tillgodose kylbehovet på jämfört med de kompressorkylmaskiner som finns i referensbutiken. I den andra delen av projektet var målet att bygga upp en modell av referensbutiken i ett energiberäkningsprogram och att simulera energieffektiviserande lösningar på denna. Detta för att undersöka hur mycket energibesparingar som kunde erhållas, framförallt i minskat uppvärmningsbehov per år.

    De metoder som användes för utförandet av detta arbete var studiebesök, intervjuer, kontakt med företag, litteratursökning och datorsimuleringar. Inledningsvis utfördes ett studiebesök på referensbutiken för att få en överblick över dess utformning och uppbyggnad. För undersökningen av fjärrvärme, bergvärme och solceller upprättades kontakt med olika leverantörer medan undersökningen av alternativa kylmetoder utfördes som en litteraturstudie. För den andra delen av projektet valdes IDA Indoor Climate and Energy (IDA ICE) att användas som energiberäkningsprogram. Referensbutiken modellerades i programmet och fick sedan fungera som grundfall på vilken ett antal, utvalda energieffektiviserande lösningar testades.

    De viktigaste slutsatserna i detta projekt är att när värmesystem ska väljas för den nya butiken så är fjärrvärme ett mer lönsamt alternativ när valet står mellan fjärrvärme och bergvärme. Slutsatsen för den del i projektet där solceller undersöktes är att det är en lönsam investering att installera solceller på den nya butiken utifrån de beräkningar som har erhållits från två leverantörer. Det bästa alternativet var en tunnfilmssolcell som gav en återbetalningstid på cirka sju år och en investeringskostnad på cirka 1,5 miljon kronor om statsbidraget erhålls. Av det totala elbehovet skulle då cirka 20 % täckas av produktionen från solcellspanelerna. Slutsatserna som kan göras när de energieffektiviserande lösningarna testades var att de två som gav störst energibesparing var behovsstyrning av ventilationsflödet och minskad belysningseffekt. Dessa två energieffektiviserande lösningar rekommenderas att undersökas närmare för att utreda möjligheten att implementera i den nya butiken.

  • 157.
    Angelica, Nordin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    En studie om typografins betydelse i analogt format2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract (EN)

    This paper is the final part of the Media Producer Program at Umeå University, including a supplementary year. This essay is a Bachelor thesis in media technology.

    The purpose of this was to deepen my knowledge and extend my skills in graphic design, especially for printing. The goal was to find an answer to the question "what is the significance of typography in the analog format?". Another purpose was to test the hypothesis "it is harder to read text written in a different color than black on a white/light background".

    This thesis are for those who are interested in typography and its importance. The thesis also refer to the history about typography, the structure and basic rules. It also presents a survey of its significance in the analog format. Not a statistical survey, but an empirical study that captures a bunch of opinions and values ​​about the use of typography.

    The results of the survey are presented with texts and tables, and it shows a disagreement to what the literature says. The result shows that people read text written with sans-serifs rather than text written with serifs. It also shows that people doesn’t thinks it’s harder to read text written with other colors than black on light backgrounds.

     

    The result of the side project appears with texts and pictures, so you  can get an overview about the layout and how the results of the study, and the theory, are implicated.

    In the essay I have also looked at scientific articles. You can read about that in the discussion section, where you also find suggestions to further studies and research in typography, as well as thoughts on the work in its entirety.

  • 158.
    Anjomshoae, Sule
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Najjar, Amro
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Calvaresi, Davide
    Främling, Kary
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Explainable Agents and Robots: Results from a Systematic Literature Review2019In: AAMAS '19: Proceedings of the 18th International Conference on Autonomous Agents and MultiAgent Systems / [ed] N. Agmon, M. E. Taylor, E. Elkind, M. Veloso, International Foundation for Autonomous Agents and MultiAgent Systems , 2019, p. 1078-1088Conference paper (Refereed)
    Abstract [en]

    Humans are increasingly relying on complex systems that heavily adopts Artificial Intelligence (AI) techniques. Such systems are employed in a growing number of domains, and making them explainable is an impelling priority. Recently, the domain of eXplainable Artificial Intelligence (XAI) emerged with the aims of fostering transparency and trustworthiness. Several reviews have been conducted. Nevertheless, most of them deal with data-driven XAI to overcome the opaqueness of black-box algorithms. Contributions addressing goal-driven XAI (e.g., explainable agency for robots and agents) are still missing. This paper aims at filling this gap, proposing a Systematic Literature Review. The main findings are (i) a considerable portion of the papers propose conceptual studies, or lack evaluations or tackle relatively simple scenarios; (ii) almost all of the studied papers deal with robots/agents explaining their behaviors to the human users, and very few works addressed inter-robot (inter-agent) explainability. Finally, (iii) while providing explanations to non-expert users has been outlined as a necessity, only a few works addressed the issues of personalization and context-awareness

  • 159.
    Annamalai, Alagappan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics. Division of Biotechnology, Advanced Institute of Environmental and Bioscience, College of Environmental and Bioresource Sciences, Chonbuk National University, Republic of Korea.
    Lee, Hyun Hwi
    Choi, Sun Hee
    Lee, Su Yong
    Gracia-Espino, Eduardo
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Subramanian, Arunprabaharan
    Park, Jaedeuk
    Kong, Ki-jeong
    Jang, Jum Suk
    Sn/Be Sequentially co-doped Hematite Photoanodes for Enhanced Photoelectrochemical Water Oxidation: Effect of Be2+ as co-dopant2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 23183Article in journal (Refereed)
    Abstract [en]

    For ex-situ co-doping methods, sintering at high temperatures enables rapid diffusion of Sn4+ and Be2+ dopants into hematite (alpha-Fe2O3) lattices, without altering the nanorod morphology or damaging their crystallinity. Sn/Be co-doping results in a remarkable enhancement in photocurrent (1.7 mA/cm(2)) compared to pristine alpha-Fe2O3 (0.7 mA/cm(2)), and Sn4+ mono-doped alpha-Fe2O3 photoanodes (1.0 mA/cm(2)). From first-principles calculations, we found that Sn4+ doping induced a shallow donor level below the conduction band minimum, which does not contribute to increase electrical conductivity and photocurrent because of its localized nature. Additionally, Sn4+-doping induce local micro-strain and a decreased Fe-O bond ordering. When Be2+ was co-doped with Sn4+-doped alpha-Fe2O3 photoanodes, the conduction band recovered its original state, without localized impurities peaks, also a reduction in micro-strain and increased Fe-O bond ordering is observed. Also the sequence in which the ex-situ co-doping is carried out is very crucial, as Be/Sn co-doping sequence induces many under-coordinated O atoms resulting in a higher micro-strain and lower charge separation efficiency resulting undesired electron recombination. Here, we perform a detailed systematic characterization using XRD, FESEM, XPS and comprehensive electrochemical and photoelectrochemical studies, along with sophisticated synchrotron diffraction studies and extended X-ray absorption fine structure.

  • 160.
    Ansari, Hamon
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Performance Comparison of Two Database Management Systems MySQL vs MongoDB2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Databases are commonly used today in a vast amounts of applications. The main point in using databases is to be able to store and access data fast and in a secure way. These databases need to be able make different operations as fast as possible without losing data. The two main database technologies used today are NoSQL and SQL (StructuredQuery Language) databases. NoSQL is an umbrella term for all DBMS (Database Management system) which are not using SQL like relational databases do. NoSQL stands for non-SQL, non-relational or not only SQL.

    In this thesis one DBMS from each database technology is compared to each other. The comparison is based on space allocation when they contain different amounts of records and time performance when executing different operations on different amounts of records. The operation stested for the speed performance were insertion, select, update and remove.

    The results showed that MySQL allocated less space when containing large amounts of records. While MongoDB was faster in almost all test case for every operation.

  • 161.
    Anugwom, Ikenna
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Laboratory of Industrial Chemistry and Reaction Engineering, Process Chemistry Centre, Åbo Akademi University, Åbo-Turku FI-20500, Finland.
    Rujana, L.
    Wärnå, J.
    Hedenström, Mattias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Laboratory of Industrial Chemistry and Reaction Engineering, Process Chemistry Centre, Åbo Akademi University, Åbo-Turku FI-20500, Finland.
    In quest for the optimal delignification of lignocellulosic biomass using hydrated, SO2 switched DBU MEASIL switchable ionic liquid2016In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 297, p. 256-264Article in journal (Refereed)
    Abstract [en]

    In this paper, various process parameters aiming at optimal short-time-high-temperature (STHT) process were studied upon fractionation of Nordic woody biomass into its primary constituents. Highly diluted, aqueous 'SO2-switched' switchable ionic liquid (SIL) based on an alkanol amine (monoethanol amine, MEA) and an organic superbase (1,8-diazabicyclo-[5.4.0]-undec-7-ene, DBU) was applied. The ultimate goal was to develop a more sustainable, environmentally friendly and cost efficient systems for efficient separation of the lignocellulosic fractions. One of the main products from the SIL fractionation is cellulose-rich pulp with very low lignin content, complemented with hemicelluloses. The NMR results reveal that substantial removal of lignin occurs even when relatively low amount of SIL was used. Further, a simple mathematical model describing the dissolution of the lignocellulose components (hemicellulose and lignin) and weight loss of wood as a function of time is described. Moreover, the most efficient process involved the use of SpinChem (R) rotating bed reactor while upon use of a flow through (loop) reactor, promising results were obtained at a treatment time of 4 h. Still, all the reactor systems studied gave rise to a rather low removal of hemicelluloses which mean that the solvent system is primary selective towards lignin dissolution.

  • 162.
    Apelqvist, Bo-Isak
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning av LKAB:s underjordsgruva i Malmberget2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The LKAB mine in Malmberget used 258 GWh of energy in 2011, broken down by different types of energy where the share is shown as a percentage in the brackets below. • Electricity 183 GWh (71%) • Diesel 4897m

    3 or 49 GWh (19%) • Fuel oil 2378 m3 or 26 GWh (10%) • Energy consumption per tonnes of production was 15.91 kWh/ton The total quantity of crude ore mined in 2011 amounted to 16 193 tonnes and energy consumption was 257 609 MWh. Corresponding figures for 2005 were 14 035 tonnes of crude ore and energy use was 219 392 MWh, which gives a figure for energy consumption per tonne of 15.63 kWh/ton. Production has increased by 15.4% and energy consumption by 17.4% from 2005 to 2011. The increase is mostly because the mining occurs at greater depths and more energy is required to transport the ore to ground level. The energy audit has been carried out with respect to the mine in Malmberget and a comparison of energy use is made with information from a previous compilation from year 2007 (base year 2005). Year 2011 is chosen as the base year for this energy audit and it is then compared to the 2005 values to get a picture of how energy use has changed since then. The survey is updated with the new main level M1250 which began to be operational during the first half of 2011. The proposed efficiency measures in chapter 5 are discussed and anchored within the company. A sectioning of responsibility for the different areas of action is made with PS, PE / PI, TP and EP included as head responsible. The proposed measures with the greatest potential savings have been identified for each area of responsibility and should be prioritized. Priority actions are ventilation heat recovery, measurement and monitoring, and interventions for behavior change.

  • 163.
    Appelblad, André
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Development of a Temperature Controlled Cell for Surface Enhanced Raman Spectroscopy for in situ Detection of Gases2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work describes a master’s thesis in engineering physics at Umeå University carried out during the spring semester of 2014. In the thesis the student has constructed and tested a temperature controlled cell for cooling/heating of surface-enhanced-Raman-spectroscopy (SERS) substrates for rapid detection of volatile substances. The thesis was carried out at the Swedish Defence Research Agency (FOI) in Umeå, Sweden. A Linkam Scientific Instruments TS1500 cell was equipped with a Peltier element for cooling/heating and a thermistor temperature sensor. A control system was constructed, based on an Arduino Uno microcontroller board and a pulse-width-modulated (PWM) H-bridge motor driver to control the Peltier element using a proportional-integral (PI) control algorithm. The temperature controlled cell was able to regulate the temperature of a SERS substrate within -15 to +110 °C and maintain the temperature over prolonged periods at ±0.22 °C of the set point temperature. Gas phase of 2-chloro-2-(difluoromethoxy)-1,1,1-trifluoro-ethane (isoflurane) was flowed through the cell and SERS spectra were collected at different temperatures and concentrations. This test showed that the signal is increased when the substrate is cooled and reversibly decreased when the substrate was heated.

    Keywords: temperature control, Raman scattering, surface enhanced Raman spectroscopy SERS, SERS substrate, volatile substances, Peltier module, thermistor, PWM, H-bridge, PI(D) control.

  • 164.
    Arad, Boaz
    et al.
    Department of Computer Science, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel.
    Balendonck, Jos
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Barth, Ruud
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Ben-Shahar, Ohad
    Department of Computer Science, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel.
    Edan, Yael
    Department of Industrial Engineering and Management, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel.
    Hellström, Thomas
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Hemming, Jochen
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Kurtser, Polina
    Department of Industrial Engineering and Management, Ben‐Gurion University of the Negev, Beer‐Sheva, Israel.
    Ringdahl, Ola
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Tielen, Toon
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    van Tuijl, Bart
    Greenhouse Horticulture, Wageningen University & Research, Wageningen, The Netherlands.
    Development of a sweet pepper harvesting robot2020In: Journal of Field Robotics, ISSN 1556-4959, E-ISSN 1556-4967Article in journal (Refereed)
    Abstract [en]

    This paper presents the development, testing and validation of SWEEPER, a robot for harvesting sweet pepper fruit in greenhouses. The robotic system includes a six degrees of freedom industrial arm equipped with a specially designed end effector, RGB-D camera, high-end computer with graphics processing unit, programmable logic controllers, other electronic equipment, and a small container to store harvested fruit. All is mounted on a cart that autonomously drives on pipe rails and concrete floor in the end-user environment. The overall operation of the harvesting robot is described along with details of the algorithms for fruit detection and localization, grasp pose estimation, and motion control. The main contributions of this paper are the integrated system design and its validation and extensive field testing in a commercial greenhouse for different varieties and growing conditions. A total of 262 fruits were involved in a 4-week long testing period. The average cycle time to harvest a fruit was 24 s. Logistics took approximately 50% of this time (7.8 s for discharge of fruit and 4.7 s for platform movements). Laboratory experiments have proven that the cycle time can be reduced to 15 s by running the robot manipulator at a higher speed. The harvest success rates were 61% for the best fit crop conditions and 18% in current crop conditions. This reveals the importance of finding the best fit crop conditions and crop varieties for successful robotic harvesting. The SWEEPER robot is the first sweet pepper harvesting robot to demonstrate this kind of performance in a commercial greenhouse.

  • 165.
    Aranovskiy, Stanislav
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. The Department of Control Systems and Informatics, National Research University of Information Technologies, Mechanics and Optics, Saint-Petersburg, Russia.
    Freidovich, Leonid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Adaptive compensation of disturbances formed as sums of sinusoidal signals with application to an active vibration control benchmark2013In: European Journal of Control, ISSN 0947-3580, E-ISSN 1435-5671, Vol. 19, no 4, p. 253-265Article in journal (Refereed)
    Abstract [en]

    An intuitive solution for the problem of adaptive attenuation of a disturbance formed as a finite sum of unknown sinusoidal signals is proposed for an internally stable discrete-time plant. The compensator is formed as a weighted sum of stable filters. An identification-based procedure for adaptive tuning of the coefficients is proposed for the case of unknown disturbance. We also propose a time-invariant compensator that provides perfect attenuation of a disturbance for the case when a model identification error is sufficiently small and disturbance frequencies are known. The technique is applied to a case study on a challenging benchmark example in the field of active vibration control. Attenuation of a disturbance formed as a sum of up to three sinusoidal signals with unknown/time-varying frequencies is demonstrated via simulation and experimental studies. (C) 2013 European Control Association. Published by Elsevier Ltd. All rights reserved.

  • 166.
    Aranovskiy, Stanislav
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Department of Control Systems and Informatics, ITMO University.
    Freidovich, Leonid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nikiforova, LV
    Department of Control Systems and Informatics, ITMO University.
    Losenkov, AA
    Department of Control Systems and Informatics, ITMO University.
    МОДЕЛИРОВАНИЕ И ИДЕНТИФИКАЦИЯДИНАМИКИ ЗОЛОТНИКОВОГО ГИДРОРАСПРЕДЕЛИТЕЛЯ: ЧАСТЬ I. МОДЕЛИРОВАНИЕ / ЧАСТЬ II. ИДЕНТИФИКАЦИЯ2013In: Scientific and Technical Journal «Priborostroenie», ISSN 0021-3454, Vol. 56, no 4, p. 253-265Article in journal (Refereed)
    Abstract [en]

    MODELING AND IDENTIFICATION OF DYNAMICS OF A HYDRAULIC ACTUATOR WITH A SPOOL VALVE. PART I. MODELING

    Approaches to the problem of modeling of hydraulic actuator are considered. A model for the spool dynamics consisting of a linear block and two static nonlinear subsystems is presented.

    MODELING AND IDENTIFICATION OF DYNAMICS OF A HYDRAULIC ACTUATOR WITH A SPOOL VALVE. PART II: IDENTIFICATION

    A method for identification of dynamic model parameters is suggested for the case when only pressures in the hydraulic cylinders but not the valve displacements are measured. The approach is verified by presented results of experiments.

  • 167.
    Aranovskiy, Stanislav
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Department of Control Systems and Informatics, ITMO University, Saint-Petersburg, Russia.
    Losenkov, Andrei
    Department of Control Systems and Informatics, ITMO University, Saint-Petersburg, Russia.
    Vazquez, Carlos
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Position control of an industrial hydraulic system with a pressure compensator2014In: Proceedings of the 2014 22nd Mediterranean Conference of Control and Automation (MED 2014), Institute of Electrical and Electronics Engineers (IEEE), 2014, p. 1329-1334Conference paper (Refereed)
    Abstract [en]

    A problem of position control of a forestry crane is studied. Several features of industrial hydraulic systems are pointed out, namely a nonlinearity of a valve and a pressure compensator. A novel model of a hydraulic system with the pressure compensator is presented and analyzed, a static nonlinearity inversion and a velocity feedforward control term are introduced. Real-time experiments with controllers which use only position measurements illustrate utility of these terms.

  • 168. Aranovskiy, Stanislav
    et al.
    Vazquez, Carlos
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Control of a single-link mobile hydraulic actuator with a pressure compensator2014In: 2014 IEEE Conference on Control Applications (CCA), 2014, p. 216-221Conference paper (Refereed)
    Abstract [en]

    A problem of position control of a single-link hydraulic drive, including model uncertainties and disturbances, is studied. Main properties of mobile hydraulic systems are taking into account, namely a nonlinearity of a valve and a pressure compensator. A discontinuous control law coupled with a static nonlinearity inversion and a feed-forward term of velocity is proposed. Besides, a novel model with pressure compensator is presented and the closed-loop stability analysis is provided. Results of experiments carried out on a forestry crane confirm the efficacy of the proposed approach.

  • 169.
    Arbuthnott, Andrew
    et al.
    Umeå University, Faculty of Social Sciences, Umeå School of Business.
    Eriksson, Jessica
    Umeå University, Faculty of Social Sciences, Umeå School of Business.
    Wincent, Joakim
    Umeå University, Faculty of Social Sciences, Umeå School of Business.
    When a new industry meets traditional and declining ones: An integrative approach towards dialectics and social movement theory in a model of regional industry emergence processes2010In: Scandinavian Journal of Management, ISSN 0956-5221, E-ISSN 1873-3387, Vol. 26, no 3, p. 290-308Article in journal (Refereed)
    Abstract [en]

    This paper takes an integrative approach towards dialectics and social movement theories in a model of regional industry emergence processes. Based on an inductive qualitative investigation we describe how a new industry emerges in a declining and peripheral region dominated by struggling and traditional local industry. The emanating model of regional industry emergence is based on four main processes; framing processes, movement mobilisation processes,inter-industry relational processes and dialectical processes, which together shape the emerging regional industry. This exemplifies how new regional industry mobilisation efforts provide an ‘anti-thesis’ to traditional industry, and how established industry actors respond with contestation to protect their business concepts. Furthermore we illustrate how new industry actors reframe their concepts to complement dominating traditional industry and to overcome tensions and conflicts. Following dialectic interaction between new and traditional industry wenoticed signs of acceptance and synthesis between the newly formed and old industry actors; ultimately resulting in a revitalisation of the region’s traditional industry. As such, this article makes a point of accounting for agency and productive conflict when understanding regional industry renewal and emergence.

  • 170.
    Arencibia, Ariel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Undersökning av fasadskivor2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this report is to present some of the market's façade panels and to do a survey of Masonite façade panels and compare. Therefore I have looked closer on potential competitors and studied their assembly method and properties. I will also propose suggestions on installing Masonite panels and improvements to the current carrying system. The carrying system for façade panels in general.

     

    Various key people in various areas of the construction industry have been interviewed. People with a wide knowledge of theory and with real work experience have been my main focuses too implement this survey. I have also collected data from the façade panel system’s properties.

     

    There are benefits with Masonites façade panel but I also found that there is a possibility to make changes to improve their properties. The improvements are only theory and not tested in practice, but it could be a good start for improvement on the façade constructions. The results of my research and my proposals are explained in more details later on in this essay.

  • 171.
    Arljung, Jerry
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Byggfysik vid prefabricerade träväggar2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The work is about prefabricated houses with wooden frames. The company that I am doing thesis examination work in units Attacus Jämtlandshus Ltd whose business is to manufacture timber frames to the building industry. This work demonstrates Jämtlandshus work process and the methods used to reach to the final product. These methods are documented in detail for possible identification activities likely to affect final product quality negatively. Also reported a large number of calculations and other values that indicate what the quality of the final product is given to heat, moisture and air tightness. The report also shows how the industries that are working with production systems use them to be as effective as they can and as competitive as possible. In reaching the above, the author used a lot from their previous experience as an employee of this company, this is above all the documentation of work processes. To perform the calculations presented, the author has made use of prior knowledge from the course, building physics, and some contact with outside professionals. The work aims to, if it is possible, to identify any weak points in production and to assess how good quality the final product is given to tightness. Both the author and Jämtlandshus think it is strange that this building technique is not bigger and more "recognized" in the market than is currently the case. By reading this report, the reader can get up their interest in prefabrication to a greater extent and start weighing the advantages and disadvantages compared with site construction. This work demonstrates the quality of these houses, and some advantages of making wooden houses by prefabrication. The author's hope through this work is that more people will open their eyes to this building techniques and that, generally, people begin to talk about these types of houses.

  • 172.
    Armgren, Marc
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Mobile Cross-platform development versus native development A look at Xamarin Platform2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The world of mobile phones is currently inhabited by three large rivals. We have Apple with their iOS devices, Microsoft with the Windows Phone line, and various devices with Googles Android operating system. Developing for all platforms individually is labour intensive and time consuming. Therefore cross-platform development is of interest for companies large as small. The technique which gives performance closest to native development is called cross compiling, which compiles native applications from a common codebase. This thesis takes a closer look at the performance of the tool Xamarin Platform, in which applications for iOS, Windows Phone and Android can be created. The performance of Xamarin Platform applications on iOS and Android is native for most user interface components. Network performance is native or better. However computational tasks are very slow compared to natively developed applications. Xamarin PlatformWindows Phone applications are not covered by this thesis.

  • 173.
    Arnlund, Caroline
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utveckling av sensor för mätning av hjärtaktivitet2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Motion analysis is a necessary tool when it comes to evaluation, monitoring and diagnosis of all the diseases that affect the human musculoskeletal system. There are only a few clinical walking laboratories in Sweden, where the patients can receive a more detailed and objective evaluation of their walking patterns. The problem with these laboratories is that they are relatively expensive and resource-demanding.

    The department of research and development at NUS has initiated a research project where AnyMo, a mobile system for measuring of moving patterns, was produced. The aim of this thesis was to further develop the existing system to simultaneously measure the electrical activity of the heart (ECG).

    The parts that were constructed during this project was an ECG sensor and a Master Unit, coupled to an existing motion sensor (part of the AnyMo system). The information that was collected from these sensors was stored locally in a memory on the system’s Master Unit.

    The finished product was tested and evaluated on a stationary bike at different pace and heart rate.

  • 174.
    Arnoldsson, Kristina
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Patrik L
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Formation of environmentally relevant brominated dioxins from 2,4,6,-tribromophenol via bromoperoxidase-catalyzed dimerization2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 13, p. 7239-7244Article in journal (Refereed)
    Abstract [en]

    Polybrominated dibenzo-p-dioxins (PBDD) are emerging environmental pollutants with structural similarities to the highly characterized toxicants polychlorinated dibenzo-p-dioxins. The geographical and temporal variations of PBDD in biota samples from the Baltic Sea do not display features that are normally related to anthropogenic sources such as incineration, and therefore the natural formation of PBDDs has been suggested. This study of the bromoperoxidase mediated oxidative coupling of 2,4,6-tribromophenol (an abundant substance that is naturally formed in marine systems) identified the formation of ppb-level yields of 1,3,6,8-tetrabromodibenzo-p-dioxin (1,3,6,8-TeBDD) through direct condensation. Additional TeBDDs (1,3,7,9-TeBDD, 1,2,4,7-TeBDD and/or 1,2,4,8-TeBDD) and tri-BDDs (1,3,7-TrBDD and 1,3,8-TrBDD) were frequently formed, but at lower yields. The formation of these TeBDDs probably proceeds via bromine shifts or Smiles rearrangements, while the TrBDDs may result from subsequent debromination processes. Since all of the congeners formed by oxidative coupling and subsequent reactions are also found in Baltic Sea biota, the results support the theory that PBDDs are formed from natural precursors.

  • 175.
    Arnqvist Eriksson, Petter
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Greppmekanism för avgasutsug på moderna bilar2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report has been carried out in cooperation with Fumex AB, which operates in Skellefteå, Sweden and develops environmental products. Auto repair shops and vehicle inspection companies today use exhaust extraction when working with vehicles to maintain a good working environment. The exhaust gas pipe design and location on the cars have changed over time, and today, most extraction nozzles have problems being attached to the exhaust pipes on modern cars.

    The aim of the project was to develop and produce a gripping mechanism that can attach a nozzle to almost all modern cars, and also develop a design proposal of the nozzle. A requirement specification was created and formed the basis for the development process.

    Systematic methods were used for concept generation and screening of ideas because design problems are often difficult to solve solely on intuition. A brainstorming session was held for the generation of ideas and the decisions was taken by means of elimination- and decision matrixes together with gut feeling. In the decision matrix the generated concepts were benchmark tested against the market-leading product.

    The gripping mechanism and the nozzle was designed in PTC Creo which is a CAD software, and the prototype of the gripping mechanism was manufactured by Nordramp AB in Skellefteå. The result is a product with relatively low complexity and which has a total production cost of 453SEK which is about 54 % of the competing company's market leading product. The product grasps exhaust tailpipes with lateral dimensions 30-95mm with about the same force regardless of the cross-sectional dimensions and shape. The weight of the product including the nozzle is calculated to be 2.2kg which is the same as the aforementioned market leading product.

    It is further proposed that the prototype of the nozzle is produced and the entire product is evaluated so that knowledge is obtained if it meets the given requirements of the requirement 

  • 176.
    Arnqvist, Kristoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av jordning för kraftproducerande anläggningar2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The safety regulations for grounding have been made stricter during later years; there are new rules and laws as well as recommendations and methods for how modern power producing facilities are to be grounded in a correct and safe manner. The purpose of this thesis has partly been to gather knowledge on these regulations as well as conducting an analysis of the grounding carried out at Vattenfalls hydro power plant G5 in Stornorrfors.

    A study of literature has been conducted and a site study was conducted with testing of earthing sites, measurement of currents and inspection of the hydro power plant G5 from a grounding perspective.

    Measurements show that the G5 power plant is a thorough and exemplary facility with very good qualities for handling earth faults., transients and preventing stray currents. The facility has a rigorous equipotential bonding where cableladders, stairs, pipes and exposed metal surfaces are all equipotentially bonded. The facility holds a good connection to earth at earthing sites when measurements revealed all earth sites having an earth resistance value less than 1 Ω. The earth sites and earth system showed only slight increases in impedance when measurements with high-frequency currents were carried out and the facility is deemed to be able to handle high-frequency currents in a satisfying manner.

    Through measurements of earth currents it was revealed that currents run in the earth wires, most likely due to the strong magnetic field generated by the generator, and it is unclear how these currents affect the earthing system and equipment over longer periods of time when some currents exceeded 10 A.

    No surge arresters were found by the facility or the transformer next to it, some were found however where the cable is replaced by hanging wires after the emergency power building. An inventory of surge arresters is recommended. The lighting protection system found on the roof of the facility should be repaired and possibly adressed in order to withstand damage caused by heavy snowfall. The facility is very exposed to the public and access to the facility should be restricted through fences and gates.

    Grounding a power producing facility today incorporates many different areas within electrical technology and therefore also holds a broad variation in how a safe installation is classified and examined. Making a facility "completely safe" is not obvious there will always be a need for compromises and considerations as no situation is similar to the next one in real life.

  • 177.
    Aronsson, Anton
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konstruktion av forcerat komponentprov: Metod för utförande av utmattningsprov på delkomponent i skördaraggregat.2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report comprises a construction of an fatigue testing equipment for a certain component at Komatsu Forest in Umeå. Testing components fatigue limit can act as compliment to the theoretical calculations. Fatigue testing equipment facilitates redesign by components because it gives fast response on whether changes was good or bad.The component this report deals with is a shaft mounted in a c144 harvester head. The axle is analysed regarding cracks, failure and through calculations with finite element method. The analysis indicates that the axle is exposed to bending forces that ultimately leads to its failure. The analysis and practical restrictions becomes the base for the design of the equipment. The equipment is designed to re-create the axles fatigue breaking through bending. Different designs regarding the equipment is discussed and also their advantages and disadvantages.The report result in complete manufacturing documents with drawings for all components and exploded views of the equipment. How the fatigue tests are done, measured, monitored and evaluated is also included in the report.

  • 178.
    Aronsson, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    NEXT-analys av kablage för Ethernetkommunikation i påfrestande miljöer2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 179. Arshadi, Mehrdad
    et al.
    Sellstedt, Anita
    Unit of Biomass Technology and Chemistry / BTK, Swedish University of Agricultural Sciences, Umea, Sweden.
    Production of energy from biomass2008In: Introduction to chemicals from biomass / [ed] James H. Clark with Fabien E.I. Deswarte, John Wiley & Sons, 2008, p. 143-178Chapter in book (Refereed)
  • 180.
    Artursson, Robin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Mätsystem för gripkraft2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Normaltryckshydrocefalus (NPH) är en sjukdom som påverkar dynamiken i cerebrospinalvätskesystemet och leder till förstorade ventriklar samt problem med gångrubbningar, urininkontinens och i vissa fall demens. I dagsläget kan det vara svårt att diagnosticera NPH-patienter då de första symptomen på sjukdomen är tendens till gångrubbningar och detta är svårt att använda som underlag då det är svårt att mäta i daglig klinik.

    I ett försök att komplettera undersökningen av NPH-patienter utvecklade jag därför på avdelningen för Medicinsk Teknik- FoU vid Norrlands Universitetssjukhus en mätutrustning med syftet att undersöka om hand- och greppkraft kan användas som underlag vid diagnos då det är enklare att mäta än att uppskatta gångrubbningar.

    Det konstruerades ett mätsystem med en styrenhet, datalogger, kraftgivare och accelerometer för att mäta kraft och acceleration i 3 axlar och spara ner denna data på ett SD-kort.

    Det färdiga mätsystemet är testat på fyra olika testpersoner och en analys är gjord på mätresultaten. I jämförelse med resultaten från en tidigare studie som bygger på mätningar med en liknande utrustning (1), uppnås goda resultat som indikerar att det färdiga mätsystemet kommer att lämpa sig väl för mätningar i den kliniska vardagen.

  • 181.
    Arvidsson, Andreas
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Bygdemark, Jörgen
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    JÄMFÖRELSE MELLAN ORACLE RDBMS, ORACLE NOSQL OCH MONGODB2019Independent thesis Basic level (degree of Bachelor of Fine Arts), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Databases are present everywhere in our modern society and the amount of data that have to be stored is constantly increasing, which means that it’s now more important than ever to be able to handle massive data sets e‚ffectively. NoSQL databases2 were developed to solve this problem by efficiently storing large amounts of data and enable fast access to that data. Since NoSQL databases only became popular within the last ten years, they haven’t been as well researched as relational databases. An in-depth evaluation is carried out on six distinct features, where one part is comparative performance tests. Th‘e other features are: scalability, consistency, availability, durability and reliability. MongoDB and Oracle NoSQL are the NoSQL databases used and together with Oracle RDBMS as relational database make up the basis for a comparative study of the above mentioned features.Th‘e results showed that there are big diff‚erences between how data is handled in NoSQL compared to relational databases that will aff‚ect the choice of database, e.g. that NoSQL tends to prioritize that clients can reach the database over non-contradictory data and lowering the demands on transaction management to increase performance and storage capacity. Furthermore, the performance tests showed that both NoSQL databases performed be‹er than the relational database regardless of the data set size. MongoDB was clearly the fastest on reading operations, while Oracle NoSQL performed write operations the fastest most of the time. Both NoSQL databases are impacted less by a growing data set than the relational database for both read and write operations.

  • 182.
    Arén, Axel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    The effect of resident related input data on the specific energy use2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 183.
    Asadpoordarvish, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Functional and Flexible Light-Emitting Electrochemical Cells2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The introduction of artificial illumination has brought extensive benefits to mankind, and during the last years we have seen a tremendous progress in this field with the introduction of the energy-efficient light-emitting diode (LED) and the high-contrast organic LED display. These high-end technologies are, however, produced using costly and complex processes, and it is anticipated that the next big thing in the field will be the advent of a low-cost and “green” illumination technology, which can be fabricated in a cost- and material-efficient manner using non-toxic and abundant raw materials, and which features attractive form factors such as flexibility, robustness and light-weight. The light-emitting electrochemical cell (LEC) is a newly invented illumination technology, and in this thesis we present results that imply that it can turn the above vision into reality.

    The thin-film LEC comprises an active material sandwiched between a cathode and an anode as its key constituent parts. With the aid of a handheld air-brush, we show that functional large-area LECs can be fabricated by simply spraying three layers of solution -- forming the anode, active material, and cathode -- on top of a substrate. We also demonstrate that such “spray-sintered” LECs can feature multicolored emission patterns, and be fabricated directly on complex-shaped surfaces, with one notable example being the realization of a light-emission fork!

    Almost all LECs up-to-date have been fabricated on glass substrates, but for a flexible and light-weight emissive device, it is obviously relevant to identify more appropriate substrate materials. For this end, we show that it is possible to spray-coat the entire LEC directly on conventional copy paper, and that such paper-LECs feature uniform light-emission even under heavy bending and flexing.

    We have further looked into the fundamental aspects of the LEC operation and demonstrated that the in-situ doping formation, which is a characteristic and heralded feature of LECs, can bring problems in the form of doping-induced self-absorption. By quantitatively analyzing this phenomenon, we provided straightforward guidelines on how future efficiency-optimized LEC devices should be designed.

    The in-situ doping formation process brings the important advantage that LECs can be fabricated from solely air-stabile materials, but during light emission the device needs to be protected from the ambient air. We have therefore developed a functional glass/epoxy encapsulation procedure for the attainment of LEC devices that feature a record-long ambient-air operational lifetime of 5600 h. For the light-emission device of the future, it is however critical that the encapsulation is flexible, and in our last study, we show that the use of multi-layer barrier can result in high-performance flexible LECs.

  • 184.
    Asadpoordarvish, Amir
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sandström, Andreas
    Edman, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Physics.
    A Flexible Encapsulation Structure for Ambient-Air Operation of Light-Emitting Electrochemical Cells2016In: Advanced Engineering Materials, ISSN 1438-1656, E-ISSN 1527-2648, Vol. 18, no 1, p. 105-110Article in journal (Other academic)
    Abstract [en]

    The emerging field of organic electronics is heralded because it promises low-cost and flexible devices, and it was recently demonstrated that a light-emitting electrochemical cell (LEC) can be fabricated with cost-efficient methods under ambient air. However, the LEC turns sensitive to oxygen and water during light-emission, and it is therefore timely to identify flexible encapsulation structures. Here, we demonstrate that a multilayer film, featuring a water and oxygen barrier property of ≈1 × 10–3 g/m2/day and ≈1 × 10–3 cm3/m2/bar/day respectively, is fit for this task. By sandwiching an LEC between such multilayer barriers, as attached by a UV-curable epoxy, we realize flexible LECs with performance on par with identical glass-encapsulated devices, and which remain functional after one year storage under air.

  • 185.
    Asadpoordarvish, Amir
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics. LunaLEC, Umeå, Sweden.
    Sandström, Andreas
    Larsen, Christian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Bollström, Roger
    Toivakka, Martti
    Österbacka, Ronald
    Edman, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Light-Emitting Paper2015In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 21, p. 3238-3245Article in journal (Refereed)
    Abstract [en]

    A solution-based fabrication of flexible and light-weight light-emitting devices on paper substrates is reported. Two different types of paper substrates are coated with a surface-emitting light-emitting electrochemical cell (LEC) device: a multilayer-coated specialty paper with an intermediate surface roughness of 0.4 μm and a low-end and low-cost copy paper with a large surface roughness of 5 μm. The entire device fabrication is executed using a handheld airbrush, and it is notable that all of the constituent layers are deposited from solution under ambient air. The top-emitting paper-LECs are highly flexible, and display a uniform light emission with a luminance of 200 cd m−2 at a current conversion efficacy of 1.4 cd A−1.

  • 186. Asan, Noor Badariah
    et al.
    Hassan, Emadeldeen
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Perez, Mauricio David
    Shah, Syaiful Redzwan Mohd
    Velander, Jacob
    Blokhuis, Taco J.
    Voigt, Thiemo
    Augustine, Robin
    Assessment of Blood Vessel Effect on Fat-Intrabody Communication Using Numerical and Ex-Vivo Models at 2.45 GHZ2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 89886-89900Article in journal (Refereed)
    Abstract [en]

    The potential offered by the intra-body communication (IBC) over the past few years has resulted in a spike of interest for the topic, specifically for medical applications. Fat-IBC is subsequently a novel alternative technique that utilizes fat tissue as a communication channel. This work aimed to identify such transmission medium and its performance in varying blood-vessel systems at 2.45 GHz, particularly in the context of the IBC and medical applications. It incorporated three-dimensional (3D) electromagnetic simulations and laboratory investigations that implemented models of blood vessels of varying orientations, sizes, and positions. Such investigations were undertaken by using ex-vivo porcine tissues and three blood-vessel system configurations. These configurations represent extreme cases of real-life scenarios that sufficiently elucidated their principal influence on the transmission. The blood-vessel models consisted of ex-vivo muscle tissues and copper rods. The results showed that the blood vessels crossing the channel vertically contributed to 5.1 dB and 17.1 dB signal losses for muscle and copper rods, respectively, which is the worst-case scenario in the context of fat-channel with perturbance. In contrast, blood vessels aligned-longitudinally in the channel have less effect and yielded 4.5 dB and 4.2 dB signal losses for muscle and copper rods, respectively. Meanwhile, the blood vessels crossing the channel horizontally displayed 3.4 dB and 1.9 dB signal losses for muscle and copper rods, respectively, which were the smallest losses among the configurations. The laboratory investigations were in agreement with the simulations. Thus, this work substantiated the fat-IBC signal transmission variability in the context of varying blood vessel configurations.

  • 187. Asan, Noor Badariah
    et al.
    Noreland, Daniel
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Hassan, Emadeldeen
    Umeå University, Faculty of Science and Technology, Department of Computing Science. Department of Electronics and Electrical Communications, Menoufia University, Menouf, Egypt.
    Shah, Syaiful Redzwan Mohd
    Rydberg, Anders
    Blokhuis, Taco J.
    Carlsson, Per-Ola
    Voigt, Thiemo
    Augustine, Robin
    Intra-body microwave communication through adipose tissue2017In: Healthcare technology letters, E-ISSN 2053-3713, Vol. 4, no 4, p. 115-121Article in journal (Refereed)
    Abstract [en]

    The human body can act as a medium for the transmission of electromagnetic waves in the wireless body sensor networks context. However, there are transmission losses in biological tissues due to the presence of water and salts. This Letter focuses on lateral intra-body microwave communication through different biological tissue layers and demonstrates the effect of the tissue thicknesses by comparing signal coupling in the channel. For this work, the authors utilise the R-band frequencies since it overlaps the industrial, scientific and medical radio (ISM) band. The channel model in human tissues is proposed based on electromagnetic simulations, validated using equivalent phantom and ex-vivo measurements. The phantom and ex-vivo measurements are compared with simulation modelling. The results show that electromagnetic communication is feasible in the adipose tissue layer with a low attenuation of approximate to 2 dB per 20 mm for phantom measurements and 4 dB per 20 mm for ex-vivo measurements at 2 GHz. Since the dielectric losses of human adipose tissues are almost half of ex-vivo tissue, an attenuation of around 3 dB per 20 mm is expected. The results show that human adipose tissue can be used as an intra-body communication channel.

  • 188. Asan, Noor Badariah
    et al.
    Redzwan, Syaiful
    Rydberg, Anders
    Augustine, Robin
    Noreland, Daniel
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Hassan, Emadeldeen
    Umeå University, Faculty of Science and Technology, Department of Computing Science. Department of Electronics and Electrical Communications, Menoufia University, Menouf, Egypt.
    Voigt, Thiemo
    Human Fat Tissue: A Microwave Communication Channel2017In: 2017 First IEEE MTT-S International Microwave Bio Conference (IMBIOC), IEEE, 2017Conference paper (Refereed)
    Abstract [en]

    In this paper, we present an approach for communication through human body tissue in the R-band frequency range. This study examines the ranges of microwave frequencies suitable for intra-body communication. The human body tissues are characterized with respect to their transmission properties using simulation modeling and phantom measurements. The variations in signal coupling with respect to different tissue thicknesses are studied. The simulation and phantom measurement results show that electromagnetic communication in the fat layer is viable with attenuation of approximately 2 dB per 20 mm.

  • 189. Asan, Noor Badariah
    et al.
    Velander, Jacob
    Redzwan, Syaiful
    Perez, Mauricio D.
    Hassan, Emadeldeen
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Blokhuis, Taco J.
    Voigt, Thiemo
    Augustine, Robin
    Effect of Thickness Inhomogeneity in Fat Tissue on In-Body Microwave Propagation2018In: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBIOC), IEEE, 2018, p. 136-138Conference paper (Refereed)
    Abstract [en]

    In recent studies, it has been found that fat tissue can be used as a microwave communication channel. In this article, the effect of thickness inhomogeneities in fat tissues on the performance of in-body microwave communication at 2.45 GHz is investigated using phantom models. We considered two models namely concave and convex geometrical fat distribution to account for the thickness inhomogeneities. The thickness of the fat tissue is varied from 5 mm to 45 mm and the Gap between the transmitter/receiver and the starting and ending of concavity/convexity is varied from 0 mm to 25 mm for a length of 100 mm to study the behavior in the microwave propagation. The phantoms of different geometries, concave and convex, are used in this work to validate the numerical studies. It was noticed that the convex model exhibited higher signal coupling by an amount of 1 dB (simulation) and 2 dB (measurement) compared to the concave model. From the study, it was observed that the signal transmission improves up to 30 mm thick fat and reaches a plateau when the thickness is increased further.

  • 190.
    Asaro, Peter M.
    Umeå University, Faculty of Arts, Humlab.
    A Body to Kick, but Still No Soul to Damn: Legal Perspectives on Robotics2012In: Robot Ethics: The Ethical and Social Implications of Robotics / [ed] Patrick Lin, Keith Abney and George A. Bekey, CAMBRIDGE: MIT Press, 2012, p. 169-186Chapter in book (Other academic)
  • 191.
    Aspholm, Mattias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av frekvensomriktaresinverkan på sin närmiljö2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Fokus läggs mer och mer på hur olinjära laster påverkar spänningsgodheten pånätet. Ledorden är att ”du skall icke sabotera din grannes spänningskvalitet!”.Detta gillar nätbolagen och allmänheten men i vissa delar av nätet är det inte lika nödvändigt att hålla så hårt på elkvaliteten. Industrier har ofta anläggningar som är avskilda öar från det elektriska fastlandet. Därför gjordes mätningar på befintlig anläggning med stor del frekvensomriktardrift för att kunna jämföra med simuleringar från dimensioneringsprogram och slutligen utifrån resultatet dra slutsatser om hur man ska utveckla tankesättet vid dimensionering av frekvensomriktare för att göra den mer kostnadseffektiv.

  • 192. Asplund, Disa
    et al.
    Westin, Jonas
    Umeå University, Faculty of Social Sciences, Centre for Regional Science (CERUM).
    Modellering av slingor inom sjötransporter2017Report (Refereed)
    Abstract [en]

    The Swedish national freight transport model system Samgods is a freight model that simulates logistics decision at a disaggregated firm-to-firm level. The model calculates total annual transport demand in Sweden for all transport modes based on a deterministic cost minimization approach. The model cannot consolidate commodities of different commodity types in the same vessel, train or truck and can only simulate vessels using direct routes between two ports. This implies that many of the features of sea transport such as utilizing larger vessels and building loops to consolidate goods from different ports is not possible in the current Samgods version. In this paper, we analyze the effect of removing restrictions in sea transportation especially by allowing the ship operators to construct and utilize loops. In the new model, LIFREM (Loops Including FREight Model), the shippers’ choice of sea transport routes is modelled as a mixed integer linear programming optimization problem. In doing so, we make use of a case study on sea transport of forest products from Northern Sweden to Western Europe. The results show that allowing predefined loops decreases total logistic cost by 10% and allowing the shipper to freely select loops decreases the cost by 21%. These results show that modelling of loops is important in order to realistically represent the attractiveness of the sea transport mode. This is also confirmed by the fact that the sea mode share increases by 2–4% in LIFREM when loops are allowed.

  • 193.
    Asplund, Jesper
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Processkartläggning och metodstudier på Ålö AB2014Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
  • 194.
    Asplund, Jesper
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Processkartläggning och metodstudier på Ålö AB2014Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport är resultatet av examensarbete för högskoleingenjörsexamen i maskinteknik förlagt vid Ålö AB.

    Ålö är en världsledande tillverkare av frontlastare, redskap och fundament för jordbrukstraktorer. Vid produktionsanläggningen i Brännland utanför Umeå tillverkas en mängd olika varianter av lastare.

    Projektet omfattar processkartläggning av förbehandlingsprocessen som en lastare genomgår innan den målas. Vid en internrevision uppdagades brister inom processorientering vid förbehandlingen. Processorientering är en av Ålös bärande principer och viktigt för att säkerställa att arbetet sker enligt korrekta rutiner, instruktioner och system. Detta säkerställs delvis genom att Ålö beskriver sin verksamhet med processkartor, nedbrytbara i flera nivåer.

    Projektets mål var att skapa en processkarta över arbetsmoment och rutiner vid förbehandlingen. Syftet var att på sikt hjälpa Ålö standardisera sina arbetssätt och förbättra sitt processorienterade arbete.

    Information om processen inhämtades genom workshops, praktik och litteraturstudier. Arbetet resulterade i en processkarta över förbehandlingsprocessen samt en tillhörande handbok för att ge en sammanfattande beskrivning av processen. Rapporten avhandlar även grundläggande begrepp och metoder relaterade till processkartläggning.

    Resultatet visar att processen överlag har en hög mognadsgrad, där det huvudsakliga problemet är bristande dokumentation. En brist som detta projekt delvis avhjälper, men som kräver fortsatt arbete med processkartläggning och arbetsinstruktioner.

  • 195.
    Asplund, Jonas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Maskin för simulering av tuggprocessen: - för utveckling av implantat inom protetik2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En vanlig behandling av tandlöshet i underkäken är att operera in fyra titanimplantat och på implantaten göra en tandbrygga. Om munhygienen är bristfällig kan komplikationer uppstå med risk för att implantaten lossnar. Med färre implantat skulle den risken kunna minska.

     Syftet var att konstruera och tillverka en maskin för simulering av tuggprocessen. Användningen av maskinen ska kunna avgöra om hållfastheten är tillräcklig med endast två implantat. Maskinen tillverkades enligt en kravspecifikation i verkstaden i Teknikhuset, Umeå universitet, på uppdrag av Tomas Lindh vid Institutionen för odontologi vid Umeå universitet. Maskinen skulle b la kunna belasta implantaten och tandbryggan med en kraft som maximalt kan uppkomma i underkäken på en människa, ca 1 kN.

    Maskinen konstruerades med elmotor som driver en växel med kuggremsdrift som sköter den mekaniska tuggningen. Kamhjulet bestod av fyra kammar för jämna tryckpulser. Resultatet blev en maskin med en acceptabel konstruktion som uppfyllde de ställda kraven och gav en tryckkraft från ca 350 till 1 kN beroende på hur fjäderns förspänning ställdes. Tillverkningen begränsades framför allt av ekonomi och tid, vilket gjorde att en alternativ konstruktion med vevaxel och en färdig inköpt växel inte gick att välja.

  • 196.
    Asplund, Ragnar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av gränssnittet påWebDB3.02013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Webhotellsföretaget Vildmarksdata har haft för avsikt att uppdatera den kontrollpanel somderas kunder använder för att göra inställningar relaterade till saker som zoner, domäner ochepost. Kontrollpanelen har utvärderas efter webdesignprinciper, samtidigt som dess användarehar undersökts med hjälp av telefonintervjuer och webenkäter. Studien har resulterati en rad designförslag för en ny version av kontrollpanelen, en kartläggning av användarnaoch insikten att en stor del av kunderna inte känt till att kontrollpanelen funnits.

  • 197.
    Asplund, Raquel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Evaluation of a cloud-based image analysis and image display system for medical images2015Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
  • 198.
    Asseffa, Samrawit
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Seleshi, Bihil
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    A Case Study on Differential Privacy2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Throughout the ages, human beings prefer to keep most things secret and brand this overall state with the title of privacy. Like most significant terms, privacy tends to create controversy regarding the extent of its flexible boundaries, since various technological advancements are slowly leaching away the power people have over their own information. Even as cell phone brands release new upgrades, the ways in which information is communicated has drastically increased, in turn facilitating the techniques in which people’s privacy can be tampered with. Therefore, questioning the methodology by which people can maintain their privacy in the twenty-first century is a validated action undoubtedly conducted by the multitude of the world’s population.

    Admittedly, data is everywhere. The world has become an explosion of information, and it should not come as a surprise, especially in a time when data storage is cheap and accessible. Various institutions use this data to conduct research, track the behavior of users, recommend products or maintain national security. As a result, corporations’ need for information is growing by the minute. Companies need to know as much as possible about their customers. Nonetheless, how can this be achieved without compromising the privacy of individuals? How can companies provide great features and maintain great privacy?

    These questions can be answered by a current, anticipated research topic in the field of data privacy: differential privacy. Differential privacy is a branch of statistics that aims to attain the widest range of data while achieving a robust, significant and mathematically accurate definition of privacy.

    Thus, the objective of this thesis will be describing and analyzing the concept of differential privacy and its properties that lead to the betterment of data privacy. Hence, we will try to study the basic state-of-the-art methods, the model and the challenges of differential privacy.

    After analyzing the state-of-the-art differential privacy methods, this thesis will focus on an actual case study that is concerned with two types of different datasets which are experimented with one of the methods of differential privacy methods. We design a basic framework that tries to achieves differential privacy guarantee and evaluate the results regarding the level of privacy achieved.

  • 199.
    Assim Jalal, Mustafa
    Umeå University, Faculty of Social Sciences, Department of Informatics.
    Mobile Service Design: The effect of platform on the use of online services: A case study exploring uses of Facebook on desktop and a mobile environment.2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Many studies looked at mobile information needs of users and how to support those needs in the mobile platform and the challenges it holds. In this study I tried to take a different approach in arguing that the uses of the services available on the stationary set up are used with different motivations and goals on the various mobile platform context and therefore designing the mobile versions of those require careful considerations of that. I present the results of a study conducted to investigate how the use of Facebook mobile differ over the stationary and mobile platform and use that as an example to elaborate on the design considerations of similar services.

  • 200.
    Astahovs, Ilja
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Travel time estimation based on previous experience - Pre-study and prototyping2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Travel time depends on various factors, which can be described by data coming from sensors. The author makes an assumption that for the same trip conditions travel time will be the same, and if we can collect enough information on the current trip conditions and find a matching trip which took place in the past, we can estimate the travel time for future trips. The project aim is to design and prototype a system capable of collecting this data, organizing, storing and using it to find matching trips, with the real-time performance being the main consideration. The scope of the system is limited by the needs of a logistic company which wants to be able to track its vehicles and estimate their travel times.

    The resulting system is tested in various settings to find out how well it performs. The author identifies the settings which are suitable for the particular implementation and suggests further improvements which are meant to extend the settings.

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