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  • 1.
    Ali, Rony
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Värmeåtervinning - styrning för frånluftsvärmepump i flerbostadshus2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 2.
    Ali, ZAKI
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Självbalansering av MinSeg2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 3.
    Andersson, Rabé
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Exploring Baxter Robot and Development of Python algorithms to Execute Holding, Lifting and Positioning Tasks2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The greatest feature of using a Baxter robot among other industrial robots is the ability to train this robot conveniently. The training of the robot could be done within a few minutes and it does not need so much knowledge of programming. However, this type of training feature is limited in functionality and needs frequent updating of the software and the license from the manufactural company. As the manufacturer of Baxter Robot no longer exists due to a merger, the thesis has twofold aims, (1) Exploring different functional, installation, calibration, troubleshooting and hardware features of the Baxter robot and (2) demonstrate the functionality of Baxter to perform general tasks of holding, lifting and moving of test objects from one desired position to another position using custom-made programs in Python. Owing to this, details about different software and hardware aspects of Baxter robot is presented in this thesis. Additionally, systematic laboratory tutorials are also presented in appendices for students who want to learn and operate the robot from simple to complicated tasks. In order to keep the Baxter operational for students and researchers in future, when there is no more help available from its manufacturer, this thesis endeavour to cover all these aspects. Thus, the thesis presents a brief understanding of how to use the Baxter Robot in a simple and efficient way to perform a basic industrial task. The kinematics part will show the concepts of forward and inverse kinematics and the DH (the Denavit–Hartenberg) parameters that are important to understand the end-effector position according to the world frame that will give the knowledge of those who are interested in the kinematics part of Baxter robot. The work of the thesis will make it easier to understand how to program a Baxter robot by using Python language and using the simplest way to move the arm to certain positions. The ROS principles, kinematics and Python language programs will provide a good platform to understand the usability of Baxter robot. Furthermore, easy to use laboratory tutorials are devised and are presented in the appendices. These laboratory tutorials will improve the understanding of the readers and provide a step-by-step guide of operating Baxter robot according to the principles of Robotics. In addition to all these points above, the thesis shows useful functions that are built in ROS (Robot Operating System) that make it easier to program the robot in an untraditional way which is one of a contribution of this thesis itself. The usual way to program the robots, in general, is to study the robot kinematics and calculate the position of the end-effector or the tool according to some frame or the world coordinate frame. This calculation can be done by the forward kinematics or the inverse kinematics. The set of programming Baxter robot in this thesis is not the complex calculation of the forward or the inverse kinematics. The tf (transform)tool in ROS has made it easier to reach the joint angles and program Baxter robot using Python.

  • 4.
    Asami-Johansson, Yukiko
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics. Department of Science Education, University of Copenhagen, Copenhagen, Denmark.
    Attorps, Iris
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Winsløw, C.
    Department of Science Education, University of Copenhagen, Copenhagen, Denmark.
    Comparing mathematics education lessons for primary school teachers: case studies from Japan, Finland and Sweden2019In: International Journal of Mathematical Education in Science and Technology, ISSN 0020-739X, E-ISSN 1464-5211Article in journal (Refereed)
    Abstract [en]

    The aim of this paper is to investigate and compare lessons given in primary school teacher education in Japan, Finland and Sweden. We analyse one lesson from each country and compare them using a common framework. Chevallard’s anthropological theory of the didactic (ATD) is used to frame this analysis and in particular to model teacher educators' didactic organization of the lessons. The focus is on how the didactic organizations of the teacher educators relate to the mathematical and didactic organizations of primary school. Based on official documents and viewpoints of the teacher educators, we also discuss how the contents and descriptions of the national curricula, and the different traditions of the teaching practices in each country, influence the didactic organizations found in the lessons. 

  • 5.
    Backman, Mathilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Se mig!: En studie om matematiskt särskilt begåvade elever2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien är att utforska vilka uppfattningar lågstadielärare har av matematiskt särskilt begåvade elever, samt undersöka vilka arbetssätt lärare har för att motivera och stimulera de här eleverna i matematik. Studien har en metod med kvalitativ ansats med en fenomenografisk och fenomenologisk inriktning. Datainsamlingsmetoden för studien är intervjuer. Fyra lärare intervjuades och de är alla något så när överens om att matematiskt särskilt begåvade elever skiljer sig från andra elever, samt på vilket sätt de gör det. Lärarnas uppfattningar av matematiskt särskilt begåvade elever överensstämmer även med tidigare forskning gällande ämnesområdet. Samtliga lärares arbetssätt innehåller extra anpassningar för de här eleverna och största skillnaden som kunnat urskiljas mellan arbetssätten är huruvida de även innehåller särskilt stöd. Till viss del överensstämmer dessa uppfattningar även med tidigare forskning då det även där råder oenigheter om matematiskt särskilt begåvade elever ska differentieras eller inte.

  • 6.
    Bautista Gonzalez, Oscar
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Integration of a Wireless Sensor Network and IoT in the HiG university2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The number of Internet of Things applications for Wireless Sensor Networks is increasing every year due to the emerging of new brands such as Big Data and Industry 4.0. With the rise of new technologies related to these fields, new opportunities have become possible with a reasonable cost, but the requirements of WSNs still being the same, where energy efficiency, robustness, scalability and others must be accomplished. The commercial hardware developed by companies can be configured through different programs to be compatible among them, taking into account multiple variables, protocols, mechanisms and options provided by new solutions. Therefore, the configuration of different devices and choosing the optimum configuration can become quite challenging due to the number of paths. In this thesis, the configuration of commercial devices provided is carried out to be able to apply this hardware in different Internet of Things applications for Wireless Sensor Networks. Transceivers, sensors of temperature, relative humidity and CO2, a gateway, and different development kits are provided on this work, where the selection of the software to set these devices is made. Repeaters are configured to be compatible with the sensors and perform under the TDMA protocol and the request-response pattern, which synchronize the communication on the network, and under the flooding mechanism, which allows to route packets through the nodes due to the short range of RF low power technologies. The connection between the WSN and the Internet is made through the GW, which is also connected to the WSN, under the TCP/IP protocol, which is configured to provide Message Queue Telemetry Transport and SecureSHell services to access the GW remotely through the Internet and send requests to the WSN automatically. Node-Red is the programming tool installed upon the GW to implement data processing, storage and visualization, via the JavaScript programming language, where the user can deploy the data, which is stored in a CSV file, to make an analysis and visualize the data and the status of the network through a live data dashboard. Finally, an experiment is carried out over the HiG university where sensors are placed to measure different halls of the university and integrate an Internet of Things application for a Wireless Sensor Network. Due to the followed process, we have been able to measure data of temperature, relative humidity and CO2 concentration levels, creating a WSN, where this data has been saved in a connected USB to the gateway. Having a performance of 90% of messages received by the GW, and we have also been able to connect the GW to the Internet, creating a system that can be accessed remotely via the MQTT broker and providing different services such as data visualization. 

  • 7.
    Berglund, Jessica
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Vill du spela bingo med mig?: En studie med laborativt material för att utveckla elevers kunskaper om positionssystemet2019Independent thesis Advanced level (degree of Master (Two Years)), 240 HE creditsStudent thesis
    Abstract [sv]

    Studiens syfte är att med hjälp av en learning study med förtest och eftertest undersöka elevers förkunskaper om positionssystemet samt om elever genom laborativt material kan fördjupa sina kunskaper om positionssystemet. Studiens teoretiska utgångspunkt är hämtad från variationsteorin. Att arbeta med ett laborativt material möjliggör för eleverna att utveckla en utökad förståelse för positionssystemet med basen 10. En av slutsatserna från denna studie är att ett variationsteoretiskt perspektiv på undervisningen underlättar lärandet.

  • 8.
    Bergroth, Simon
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Implementering av MPPT-enhet med återkoppling: avsedd för solceller2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
  • 9.
    Björk, Petter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Hur stor är sannolikheten?: En studie om traditionellt och laborativt lärande inom sannolikhetsläran2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att förklara, analysera och jämföra traditionell och laborativ undervisning inom matematikens sannolikhetslära genom learning study. Studien syftar även till att synliggöra elevernas upplevelser från de olika undervisningsmetoderna. Under en veckas matematiklektioner är klassens elever indelas i en kontroll- och testgrupp. Med hjälp av för- och eftertest, traditionell och laborativ undervisning inom sannolikhetslära, enkäter och anteckningar jämförs elevernas resultat och skillnader i elevernas uppfattningar. Learning study påvisar en ökning av elevernas kunskaper beträffande sannolikhetslära i grupperna. Eleverna i testgruppen framlägger även positiva åsikter beträffande de laborativa undervisningstillfällena.

  • 10.
    Blank, Jonathan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Motivation till matematik: En kvalitativ studie om hur elever i årskurs 4–6 kan motiveras i matematikundervisningen ur ett lärarperspektiv2019Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka hur lärare arbetar med att motivera elever i årskurs 4–6 i matematik. För att undersöka detta genomfördes klassrumsobservationer och semistrukturerade intervjuer med tre verksamma lärare i årskurs 4–6. Studiens resultat visar att en hög motivation hos eleverna skapas av tydliga strukturer i klassrummet, att läraren synliggör målen för eleverna, att läraren varierar sina arbetssätt och undervisningsformer samt att eleven tar ansvar för sitt eget lärande. 

  • 11.
    Bui, Tuyet T. A.
    et al.
    Laboratory of Fruit Breeding and Biotechnology, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium.
    Wright, Sandra A. I.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Biology.
    Falk, Anders B.
    Valthornsvagen, Uppsala, Sweden.
    Vanwalleghem, Tanja
    Department of Mycology, Proefcentrum Fruitteelt vzw, Sint-Truiden, Belgium.
    Van Hemelrijck, Wendy
    Department of Mycology, Proefcentrum Fruitteelt vzw, Sint-Truiden, Belgium.
    Hertog, Maarten L.A.T.M.
    Division of MeBioS, Department of Biosystems, Faculty of Bioscience Engineer-ing, KU Leuven, Leuven, Belgium.
    Keulemans, Johan
    Laboratory of Fruit Breeding and Biotechnology, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium.
    Davey, Mark W.
    Laboratory of Fruit Breeding and Biotechnology, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium.
    Botrytis cinerea differentially induces postharvest antioxidant responses in 'Braeburn' and 'Golden Delicious' apple fruit2019In: Journal of the Science of Food and Agriculture, ISSN 0022-5142, E-ISSN 1097-0010Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The fruit of two apple cultivars - 'Braeburn', which is susceptible to inoculation with Botrytis cinerea, and the less susceptible cv. 'Golden Delicious' - were investigated with respect to their response to inoculation with B. cinerea. Successful infection by B. cinerea leads to an oxidative burst and perturbation of plant redox homeostasis. To investigate the interaction between apple fruit and B. cinerea, antioxidant metabolism in fruit samples from sun-exposed and shaded sides of different tissue types was measured over time.

    RESULTS: The sun-exposed tissue of 'Braeburn' had higher initial levels of total vitamin C in the peel and phenolic compounds in the flesh than 'Golden Delicious', despite its greater susceptibility to gray mold. A substantial antioxidant response was recorded in diseased 'Braeburn' fruit 14 days after inoculation, which involved an elevated superoxide dismutase activity and ascorbate peroxidase activity, a progressive oxidation of total vitamin C, and a decrease in peroxidase activity and phenolic content. Disease development was slower on the sun-exposed sides than on the shaded sides.

    CONCLUSION: The two cultivars appeared to utilize different strategies to defend themselves against B. cinerea. 'Golden Delicious' almost entirely escaped infection. Preharvest exposure of apple fruit to high light / temperature stress appears to prepare them to better resist subsequent postharvest attack and disease. 

  • 12.
    Burman, Elin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Är det inne med utomhuspedagogik?: En enkätundersökning om lärares inställningar till utomhuspedagogik2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med arbetet var att undersöka lärares inställningar till utomhuspedagogik. Genom att belysa möjligheter och redogöra för hinder för utomhuspedagogisk verksamhet kan arbetet inspirera och motivera lärare och lärarstudenter till att använda sig av utomhuspedagogik, samt skapa diskussion. Den datainsamlingsmetod som använts i detta arbete är en webbaserad enkätundersökning som distribuerats via mejl till skolor i Stockholm. Resultatet visar att samtliga lärare som svarade ser möjligheter med utomhuspedagogik där ökad förståelse, möjligheten att upptäcka och uppleva naturen samt hälsofrämjande aspekter är de mest framträdande. Resultatet visar att det största hindret är bristen på personal. Resultatet visar även att lärare på skolor i innerstaden, upplever närmiljön som ett större hinder än lärare på skolor utanför innerstaden. Min undersökning visar på flera möjligheter med utomhuspedagogisk verksamhet.

  • 13.
    Christensen, Simon
    et al.
    Aalborg University, Aalborg, Denmark.
    Bai, Shaoping
    Aalborg University, Aalborg, Denmark.
    Rafique, Sajid
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Isaksson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    O'Sullivan, Leonard
    University of Limrick, Limerick, Ireland.
    Power, Valerie
    University of Limrick, Limerick, Ireland.
    Virk, Gurvinder Singh
    Innovative Technology and Science Limited, Cambridge, United Kingdom.
    AXO-SUIT: A Modular Full-Body Exoskeleton for Physical Assistance2019In: Mechanism Design for Robotics: Proceedings of the 4th IFToMM Symposium on Mechanism Design for Robotics / [ed] Alessandro Gasparetto and Marco Ceccarelli, Cham: Springer Netherlands, 2019, Vol. 66, p. 443-450Chapter in book (Refereed)
    Abstract [en]

    This paper presents the design of a modular full-body assistive exoskeleton (FB-AXO) for older adults which was developed with funding under the AAL funded AXO-SUIT project. Processes used to formulate a prioritized set of functional and design requirements via close-end-user involvement are outlined and used in realizing the exoskeleton. Design of the resulting mechanics and electronics details for the lower and upper-body subsystems (LB-AXO and (UB-AXO)) are described. Innovative designs of shoulder and spine mechanisms are presented. TheFB-AXO system comprises 27 degrees of freedom, of which 17 are passive and 10 active. The exoskeleton assists full-body motions such as walking, standing, bending, as well as performing lifting and carrying tasks to assist older users performing tasks of daily living.

  • 14.
    Dahlqvist, Rebecka
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Kan lika gärna skriva siffrorna upp och ner, det står väl samma sak ändå?: En studie om hur lärarna upptäcker och hjälper elever med matematiksvårigheter2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att ta reda på hur lärarna upptäcker och hjälper elever med matematiksvårigheter. För att kunna besvara undersökningens frågeställningar har kvalitativa intervjuer gjorts med olika lärare. Resultatet analyserades med hjälp av kognitivismen och konstruktivismens som mitt analysverktyg. Undersökningen visar på att lärarna var eniga om vilka tydliga tecken som var specifikt för matematiksvårigheter, eleverna tappar koncentrationen och räknar oftast på fingrarna istället för huvudräkning. En del lärare var positiva till digitala verktyg i undervisningen medan andra föreslog hellre praktiskt material till eleverna med svårigheter. Det som kan tänkas ligga till grund för matematiksvårigheter är motivationen och nivån på undervisningen.

  • 15.
    Danarp, Pernilla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Att lära biologi: Lärares och elevers uppfattning om motivationsfaktorer2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien var att synliggöra hur lärare arbetar för att försöka motivera elever i ämnet biologi samt undersöka i vilken grad eleverna uppfattar lärares olika motivationfaktorer som viktiga för deras egen motivation. Studien har genomförts via lärarintervjuer samt via elevenkäter. Intervjuresultatet visade att lärare i årskurs två och tre i sina försök att motivera elever lyfte motivationsfaktorer utifrån delaktighet, skapa intresse, läraregenskaper, arbetsmetoder, undervisningsrum, föräldraengagemang, bekräftelse, relationer och föräldraattityd. Lärarnas motivationsarbete motsvarade till stor del elevernas egna motivationsfaktorer. Det som minst svarade mot elevernas motivationsfaktorer var bekräftelse från andra. Enkätsvaren lyfter fram betydelsen av goda relationer och bra samarbete samt betydelsen av att eleven får hjälp av läraren och förstår undervisningsmaterialet. I resultatet framkommer att både lärare och elever i högre grad betonar motivatorer som är kopplade till inre motivation än till motivatorer kopplade till yttre motivation.

     

  • 16.
    Dong, Lili
    et al.
    Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
    Sun, Tao
    Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
    Berg, Björn
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Biology. Department of Forest Sciences, University of Helsinki, Helsinki, Finland.
    Zhang, Lili
    National Engineering Laboratory for Soil Nutrient Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
    Zhang, Quanquan
    School of International Education, Beijing University of Chemical Technology, Beijing, China.
    Wang, Zhengwen
    Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
    Effects of different forms of N deposition on leaf litter decomposition and extracellular enzyme activities in a temperate grassland2019In: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 134, p. 78-80Article in journal (Refereed)
    Abstract [en]

    Despite the importance of decomposition for biogeochemical cycles, it is still not clear how this process is affected by different forms of nitrogen (N). Equal amounts of N with different ratios of inorganic N: organic N (0 : 0, 10 : 0, 7 : 3, 5 : 5, 3 : 7, and 0 : 10) were added to the soil in a steppe. We studied the response of litter decomposition to different forms of N enrichment. The treatment with 30% organic N resulted in the fastest decomposition, which was higher than with inorganic N or organic N addition alone. Our results highlight the need for studies of N deposition on carbon cycles that consider different components in N deposition.

  • 17.
    Ehl, Stefan
    et al.
    Biogeography, Trier University, Trier, Germany; Senckenberg German Entomological Institute, Müncheberg, Germany.
    Holzhauer, Stephanie I. J.
    Senckenberg German Entomological Institute, Müncheberg, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany.
    Ryrholm, Nils
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Biology.
    Schmitt, Thomas
    Senckenberg German Entomological Institute, Müncheberg, Germany; Entomology, Department of Zoology, Institute of Biology, Faculty of Natural Sciences I, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
    Phenology, mobility and behaviour of the arcto-alpine species Boloria napaea in its arctic habitat2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, no 1, article id 3912Article in journal (Refereed)
    Abstract [en]

    Arctic and alpine environments present extreme, but different, challenges to survival. We therefore studied the ecological adaptation of the arctic-alpine fritillary Boloria napaea in northern Sweden and compared these results with the eastern Alps. Using mark-release-recapture, we analysed phenology, mobility, activity patterns, change in wing condition and nectar sources. The phenology showed no protandry, but a longer flight period of the females. Wing conditions revealed a linear decay being quicker in males than females. The mean flight distances were higher for males than females (143 vs 92 m). In general, males were more flight active, while females invested more time in feeding and resting. The shortness of the flight period in the Arctic is apparently a particular adaptation to these harsh conditions, not even allowing protandry, and constraining all individuals to hatch during a short period. These conditions also forced the individuals to concentrate on flight and alimentation. In general, Arctic and Alpine populations of B. napaea show few differences, but the species seems to be even better adapted to the northern environments. Thus, the short temporal separation of these populations seems not to have been sufficient for a divergent adaptation in the southern mountains.

  • 18.
    Enterfeldt, Caroline
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Specialundervisning i matematik2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 19.
    Fried, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Relevansen i dagens matematikinnehåll för gymnasieskolans yrkesprogram enligt Skolverkets läroplan Lgy-112019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med examensarbetet är att ta reda på hur relevant matematiken är för eleverna på yrkesprogrammen. Detta med anledning av att den här kategorin elever har högst andel elever med låg motivation och med låga meritvärden från grundskolan. Hur kan undervisningen bedrivas för bästa resultat och förståelse så den går att applicera på det kommande yrket men samtidigt också vara allmänbildande. Matematiken som yrkeseleverna lär sig idag ska vara både allmänbildande och yrkesrelaterad. Den allmänbildande matematiken är lika för alla yrkeselever medan den karaktärsrelaterade matematiken varierar. Med anledning av detta så är de nationella proven konstruerade på så sätt att de tar upp enbart den allmänna kunskapen i matematik. Därför finns också funderingar om varför yrkeselever behöver göra de nationella proven. För att försöka få svar på frågorna har intervjuer genomförts med ämneslärare, yrkeslärare på båda programmen och elever från vartdera programmet. Även elev som gått i skolan men är yrkesverksam nu har intervjuats.  Även Studier har gjorts mot tidigare forskning inom områden som berör yrkeselevernas matematikundervisning, deras svårigheter med matematik och hur de kan bli motiverade. Resultaten från intervjuerna jämfördes sedan mot den litteratur som studerats. Valet av yrkesinriktningar föll på Bygg- och anläggningsprogrammet samt Barn- och fritidsprogrammet då det är inom dessa inriktningar jag varit i kontakt med tidigare. Resultatet visar att matematiken är relevant då det är ämneslärarens uppgift att förhålla sig till den matematik som är nödvändig men att kursböckerna är allom rådande i de flesta fall. Matematikundervisningen ger bäst resultat för yrkesrelaterade kunskaper om matematikläraren samarbetar med yrkeslärarna vilket både intervjuerna och forskning visar. De nationella proven ansågs av de flesta som något bra då syftet med de nationella proven är att mäta den allmänna matematikkunskapen hos eleverna.

  • 20.
    Gautam, Mukesh Kumar
    et al.
    Division of Earth and Environmental Sciences, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea; Biology Department, Medgar Evers College, City University of New York, New York, NY, USA.
    Lee, Kwang-Sik
    Division of Earth and Environmental Sciences, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea.
    Berg, Björn
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Biology. Department of Forest Sciences, University of Helsinki, Helsinki, Finland.
    Song, Byeong-Yeol
    Division of Earth and Environmental Sciences, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea; Chemical Analysis Division, National Forensic Service, Wonju, Republic of Korea.
    Yeon, Jeh-Yeong
    Division of Earth and Environmental Sciences, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea.
    Trends of major, minor and rare earth elements in decomposing litter in a cool temperate ecosystem, South Korea2019In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 222, p. 214-226Article in journal (Refereed)
    Abstract [en]

    The decomposition dynamics of 34 different elements in four different litter types (foliar and woody litter) from Pinus densiflora (Korean red pine) and Castanea crenata (Korean chestnut) was investigated in a cool temperate ecosystem using the litterbag method. Two contrasting trends were observed in the dynamics of elements with accumulated mass loss of litter and carbon. Leaf litter of Korean chestnut, which was richer in elements, showed a general decrease in concentrations of elements with accumulated mass loss of litter and carbon on a dry mass basis during decomposition in the field. Other litter types, with initially lower concentrations of elements, exhibited an increase in concentration on a dry mass basis during field incubation. Highest relative increase in the concentration was noticed for the minor elements, and for the woody litters. Concentrations of major and minor elements increased by factors ranging from 1.07 for antimony (Sb) to 853.7 for vanadium (V). Rare earth elements (REE) concentrations increased by factors ranging from 1.04 for scandium (Sc) to 83.5 for thorium (Th). Our results suggest that litter type plays an important role for nutrient dynamics. Results from principal component analysis for major, minor, and rare earth elements showed grouping of elements and high correlation among them (P < 0.05), which suggests a common source. At both sites, element concentrations were high in the soil, especially for REE. This suggests that increase in element concentrations during field incubation probably was due to transfer of elements from soil to the overlying decomposing litter.

  • 21.
    Gustafsson, Kajsa
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Rörelse för lärande: Vilka är lärares kunskaper om och deras förhållningssätt till fysisk aktivitet för ökad inlärning?2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Denna studies syfte var att undersöka lärare och lärarstudenters kunskaper och uppfattningar om fysisk aktivitet för ökad inlärning. Vilka möjligheter som skolor ges till fysisk aktivitet var också ett av studiens syfte. Studien har en kvalitativ forskningsansats genom att enkäter med slutna frågor har använts tillsammans med uppföljande semistrukturerade intervjuer som metod för att besvara studiens forskningsfrågor. Arton lärare har genomfört enkät via skolbesök och sex av dem har deltagit i uppföljande intervjuer. Dessutom har 246 respondenter besvarat enkäten via länk i sociala medier. Resultatet visar på att lärare och lärarstudenter har uppfattningen om att fysisk aktivitet är en viktig faktor för inlärning. Resultatet visar även att den fysiska aktiviteten har positiva bieffekter inte bara på hjärnans funktioner utan även på elevernas sociala utveckling. Respondenterna i studien är eniga om att fysisk aktivitet påverkar elevers inlärning vilket borde motivera ännu fler till att använda och utforska metoden.

  • 22.
    Gustrin, Malin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Utomhuspedagogik: Hur kan man implementera regelbunden utomhuspedagogik i Grundskolan åk 1-3?2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 23.
    Hadin, Joacim
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    IT i matematikklassrummet: en resurs eller ett problem?: En undersökning av elevers och matematiklärares upplevelser av och inställningar till tillämpningar av IT i matematikklassrummet2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Under de senaste åren så har IT blivit ett allt mer normaliserat inslag i den svenska skolan. Även om digitaliseringen av skolan har pågått under en längre tid, så har majoriteten av den digitala utvecklingen skett under de senaste fem åren.  Även om den digitala utvecklingen har bidragit till en ökad mängd läranderesurser för lärare, så har denna rapida utveckling också medfört till att många lärare har bristande kunskaper gällande hur IT bör hanteras. En relativt betydelsefull fråga är således hur IT har påverkat den svenska gymnasieskolan. Baserat på den data som samlades in i Skolverkets (2016) studie, så kunde man konstatera att matematik är det ämne där IT används i lägst utsträckning i det svenska gymnasieklassrummet. Till följd av detta, så är utbudet av forskning kring IT:s påverkan på matematikundervisning nästintill obefintligt. Det finns därför ett samhälleligt behov av att undersöka hur IT påverkat matematikämnet. Syftet med detta arbete är följaktligen att undersöka hur IT har påverkat matematikundervisningen i den svenska skolan. För att kunna undersöka detta så har perspektiv och synpunkter från både elever och matematiklärare i den svenska gymnasieskolan samlats in och analyserats, med hjälp av blandade undersökningsmetoder. En av de slutsatser som framkommit ur studien är att många elever upplever att IT borde användas i en högre utsträckning inom matematikämnet. En annan slutsats som kan dras är att många lärare saknar kunskap och erfarenhet av att använda IT i matematikklassrummet, vilket vidare är en av de bidragande anledningarna till att många lärare väljer att inte använda IT matematikklassrummet.

  • 24.
    Hjalmarsson, Adam
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    ”Jordens resurser är inte oändliga, de tar slut och det gäller att vara rädd om våran jord”: - En kvalitativ intervjustudie gällande lärares användning av utomhuspedagogik angående hållbar utveckling2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien är att undersöka lärares uppfattningar av utomhuspedagogik med avseende på hållbar utveckling i urbana miljöer med inriktning på naturvetenskap och teknik under grundskolans tidiga år. Studiens utformning var av kvalitativ karaktär med intervjuer. Inter- vjuerna gjordes med semi-strukturerade intervjufrågor för att svara mot studiens syfte. Urvalet bestod av sex lärare som undervisar i grundskolans tidiga år från skolor i västra Sverige.

    Alla lärare förmedlar en positiv inställning till att bedriva utomhuspedagogik. De menar att de anser att det är viktigt att förmedla hållbar utveckling till eleverna eftersom det är de som är ”framtiden”. Majoriteten av lärarna i studien beskriver att de undervisar mindre utomhus nu än för tio år sedan. Dessutom, har flera av lärarna svårt att beskriva utomhusaktiviteter för att förmedla hållbar utveckling. Det finns flera olika anledningar till varför lärarna i studien inte undervisar utomhus gällande hållbar utveckling men även i andra ämnen. Anledningarna be- skrivs av lärarna som elevgrupper, stress, planering, tidsbrist och okunskap.

  • 25.
    Holmgren, Elin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Matematikinlärning med digitala verktyg för årskurserna F-3: - En studie som jämför svenska digitala verktyg med internationell forskning inom ämnet.2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 26.
    Händel, Peter
    et al.
    Department of Information Science and Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Modeling Mixer and Power Amplifier Impairments2019In: IEEE Microwave and Wireless Components Letters, ISSN 1531-1309, E-ISSN 1558-1764, Vol. 29, no 7, p. 441-443, article id 8733818Article in journal (Refereed)
    Abstract [en]

    Combating the effects of mixer and power amplifier (PA) imperfections on transmitter performance is crucial for the design of wireless systems. PA compression and in-phase/quadrature imbalance are analyzed for a single-input-single-output transmitter model. The influence of the imperfection on the normalized mean squared error (NMSE) of the transmitter is studied using an analytical framework that relies on the classic Bussgang theory. The study concludes with a closed-form expression for the NMSE that provides insights into the behavior of the transmitter. © 2019 IEEE.

  • 27.
    Ivanchenko, Igor
    et al.
    O.Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Ukraine.
    Khruslov, Maksym
    O.Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Ukraine.
    Popenko, Nina
    O.Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Ukraine.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Combined L–S-bands antenna module2019In: IET Microwaves, Antennas & Propagation, ISSN 1751-8725, E-ISSN 1751-8733, Vol. 13, no 5, p. 541-545Article in journal (Refereed)
    Abstract [en]

    A combined L-S-band antenna module consists of four rectangular patch antennas, two of which operate at the frequencies of the first harmonics (L-band), and two others at the frequencies of the second harmonics (S-band). The module is intended for use in super heterodyne signal reception circuits, for example in studying the various non-linear phenomena. The results of this study are presented in terms of improving the performance of each antenna and minimising their mutual influence. The resonance frequencies of the L-band antenna differ by 50MHz. All the antennas radiate close to the zenith and their beamwidths in two principal planes are virtually the same. At the resonance frequencies, the reflection coefficient is S-11<-30dB for the transmitting antenna, and S-11<-20dB for the receiving antenna. The minimum allowable distance between the antennas is determined, at which their mutual influence can be neglected (S-12<-50dB).

  • 28.
    Johansson, Gustav
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Grunden till en simulering av batterier och batterisystem2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 29.
    Johansson, Sophie
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Läromedelsbokens tillämpning i NO-undervisningen för årskurs 1–3: – en läromedelsanalys samt webbenkät kopplad till läroplanens centrala innehåll för de naturorienterande ämnena i grundskolans tidigare år2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I denna undersökning så har en läromedelsanalys samt en enkätundersökning genomförts i syfte om att studera hur väl anknutna läromedelsböcker för de naturorienterande ämnena (NO) är till den svenska läroplanen Lgr11. Två läromedelsböcker har analyserats för att undersöka hur läroplanens centrala innehåll avseende naturorienterande ämnen behandlas och om det finns någonting som har uteslutits. NO-undervisningen ska behandla ämnena fysik, kemi och biologi. Det finns däremot inga nationella riktlinjer om hur undervisningstiden i de naturorienterande ämnena för årskurs 1–3 ska fördelas på dessa tre ämnena. Analys av hur läroplanens centrala innehåll i NO behandlas i läromedelsböcker visar att de olika rubrikerna från det centrala innehållet prioriteras olika högt. De punkter som handlar om djur och natur behandlas i mycket större grad än de övriga punkterna. Ämnet biologi får större plats i NO-undervisningen för årskurs 1–3 jämfört med ämnena kemi och fysik. De tillfrågade lärarna anser att läromedelsböcker ofta har tydliga kopplingar till läroplanen, speciellt det centrala innehållet, och att de flesta lärare ser stora fördelar i att använda sig av en läromedelsbok i sin NO-undervisning tillsammans med kompletterande material i form av filmer, experiment och liknande. 

  • 30.
    Kaltenböck, Viktor
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Measurement system for low frequency and low amplitude AC voltage of given frequency2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This work is about digital signal processing methods to be used to determine information of low frequency low amplitude signals of known frequency. Different adaptive filter concepts such as Wiener filter, NLMS filter and lock-in are implemented and compared to each other. The comparison carried out for different input signal amplitude and noise variance with the objective to find the best algorithm for noise cancelling. The comparison is done using a signal of interest combined with white noise as input to the filter element. The aim of the comparison is to find the most appropriate filter for further signal analyzis. The key topics for the evaluation are the efficiency of noise cancelling and ease of implementation in a data processing unit.

  • 31.
    Karlsson, Camilla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Digitala verktyg och spelifiering i matematikundervisning inriktning grundskolan f-32019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    På grund av digitaliseringskravet i läroplanen för årskurs f-3 och spelifieringens utveckling avinteraktiva program så har arbetet fokuserat på hur och i vilket syfte digitala verktyg användsinom matematikundervisningen i grundskolan f-3 samt om lärares kunskap om spelifieringkan påverka elevers resultat när de arbetar med interaktiva program inom matematiken.Undersökningar gjordes via en enkät och intervjuer med fyra verksamma lärare med olikabakgrund. Resultatet visade att digitala verktyg används ofta i matematikundervisningen ochatt den största anledningen till det var i motivationssyfte samt att det går att individualiserauppgifter. Begreppet spelifiering hade lärarna inte full kunskap om, men de var överens omatt det är viktigt för lärare att lära sig mer om begreppet för att kunna maximera sinmatematikundervisning. Den viktigaste slutsatsen blev att spelifiering är något som läraremåste komplettera sin kunskap om för att matematikundervisningen ska bli bättre samt merindividualiserad.

  • 32.
    Khulbe, Manisha
    et al.
    Ambedkar Institute of Advanced Communication Technologies and Research (AIACTR), Delhi, India.
    Tripathy, Malay Ranjan
    Amity School of Engineerng and Technology, Amity University, Noida, India.
    Parthasarathy, Harish
    Netaji Subhash Institute of Technology (NSIT), N. Delhi, India.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Lagovsky, Boris
    Russian Technological University, MIREA, Moscow, Russia.
    Inverse Scattering and Imaging Using Second Order Optical Nonlinearities2019In: 2019 6th International Conference on Signal Processing and Integrated Networks, SPIN 2019, IEEE, 2019, p. 1086-1089Conference paper (Refereed)
    Abstract [en]

    In this paper a mathematical technique is developed to find the parameters of a medium in terms of its scattered electromagnetic fields. Optical nonlinearity plays an important role in finding the scattering parameters of a medium. Using perturbation theory and nonlinear inverse scattering techniques with first order, second order and third order optical nonlinearity we find scattered electromagnetic fields. Using error minimization techniques parameters are estimated in term of permittivity and permeability up to second order. © 2019 IEEE.

  • 33.
    Krishnan, Rakesh
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics. Robotics, Perception and Learning, School of Computer Science and Communication, KTH - Royal Institute of Technology, Stockholm, Sweden; BioMEx Center, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Björsell, Niclas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Gutierrez-Farewik, Elena
    KTH Engineering Sciences, Mechanics, Royal Institute of Technology (KTH), Stockholm, Sweden; BioMEx Center, Royal Institute of Technology (KTH), Stockholm, Sweden .
    Smith, Christian
    Robotics, Perception and Learning, School of Computer Science and Communication, KTH - Royal Institute of Technology, Stockholm, Sweden; BioMEx Center, Royal Institute of Technology (KTH), Stockholm, Sweden.
    A survey of human shoulder functional kinematic representations2019In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 57, no 2, p. 339-367Article, review/survey (Refereed)
    Abstract [en]

    In this survey, we review the field of human shoulder functional kinematic representations. The central question of this review is to evaluate whether the current approaches in shoulder kinematics can meet the high-reliability computational challenge. This challenge is posed by applications such as robot-assisted rehabilitation. Currently, the role of kinematic representations in such applications has been mostly overlooked. Therefore, we have systematically searched and summarised the existing literature on shoulder kinematics. The shoulder is an important functional joint, and its large range of motion (ROM) poses several mathematical and practical challenges. Frequently, in kinematic analysis, the role of the shoulder articulation is approximated to a ball-and-socket joint. Following the high-reliability computational challenge, our review challenges this inappropriate use of reductionism. Therefore, we propose that this challenge could be met by kinematic representations, that are redundant, that use an active interpretation and that emphasise on functional understanding.

  • 34.
    Käck, Caroline
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Programmeringskompetens ur ett genusperspektiv - bland elever och lärare2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 35.
    Lagovsky, B. A.
    et al.
    Russian Technological University (MIREA), Moscow, Russia.
    Samokhin, A. B.
    Russian Technological University (MIREA), Moscow, Russia.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Regression Methods of Obtaining Angular Superresolution2019In: 2019 URSI Asia-Pacific Radio Science Conference (AP-RASC), New Dehli: IEEE, 2019, article id 8738539Conference paper (Refereed)
    Abstract [en]

    New methods of signal processing based on nonlinear regression methods are presented. They allow us to restore images of individual objects of group targets with superresolution at signal-to-noise ratios that are significantly lower than those provided by the known methods.

  • 36.
    Lie, Amber
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Vad har lärare för förutsättningar att undervisa i programmering?2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 37.
    Liljemark, Mathilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Bärande begrepp i biologi: En analys av läroplanen i biologi, skolans läroböcker och lärares läromedel i biologi2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Studiens syfte var att lyfta fram centrala begrepp i biologi utifrån det centrala innehållet i Lgr11 och se hur läromedel och lärares kursläromedel behandlar dessa begrepp. Begreppen som förekom delades upp tematiskt och ett av de teman som förekom var hållbar utveckling. Temat bestod av sex stycken begrepp och genom dessa begrepp och studiens litteraturanalys behandlades relationen mellan Lgr 11, läromedel och lärares kursläromedel. Fem läromedel för elever och 4 kursläromedel för lärare behandlas i studien.  Resultatet visar att elevers läromedel och lärares kursläromedel behandlar temat hållbar utvecklings begrepp med stor variation. Genom detta påvisar resultatet att relationen mellan Lgr11, läromedel och kursläromedel är varierande. Sammantaget visar det rent procentuellt att begreppen förekom endast i hälften av litteraturen. Med detta resultats stora variation leder det till vetskap om att det inte är självklart att begrepp, som enligt Lgr11, ska vara styrande förekommer i den utsträckning man kan förvänta sig i lärares kursläromedel och elevers läromedel. Läromedels och kursläromedlens gemensamma strategi ska vara att främst fokusera på de centrala begrepp som förekommer i Lgr11.

  • 38.
    Linde, Johanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Matematik utanför matteboken: -en idébank med praktiska övningar i matematik, utifrån LGR11 och Favorit matematik 1B2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 39.
    Ludvigsson, Fanny
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    1-3 lärares uppfattningar om utomhuspedagogik utifrån läroplanens centrala innehåll2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 40.
    Mattsson, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Zachariah, Dave
    Uppsala universitet.
    Björsell, Niclas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Flexible Models for Smart Maintenance2019In: Proceedings 2019 IEEE International Conference on Industrial Technology (ICIT), IEEE, 2019, p. 1772-1777Conference paper (Refereed)
    Abstract [en]

    Smart maintenance strategies are becoming increasingly important in the industry, and can contribute to environmentally and economically sustainable production. In this paper a recently developed latent variable framework for nonlinear-system identification is considered for use in smart maintenance. A model is first identified using data from a system operating under normal conditions. Then the identified model is used to detect when the system begins to deviate from normal behavior. Furthermore, for systems that operate on separate batches (units), we develop a new method that identifies individual models for each batch. This can be used both to detect anomalous batches and changes in the system behavior. Finally, the two methods are evaluated on two different industrial case studies. In the first, the purpose is to detect fouling in a heat exchanger. In the second, the goal is to detect when the tool in a wood moulder machine should be changed.

  • 41.
    Mellåker, Noel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science. Uppsala kommun.
    Biologiundervisning: Ett examensarbete om lärares syn på teoretisk och praktisk biologiundervisning.2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 42.
    Mixter, Susanna
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Mathiassen, Svend Erik
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Lindfors, Petra
    Stockholm University.
    Dimberg, Kenth
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Biology.
    Jahncke, Helena
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Lyskov, Eugene
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Hallman, David
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Stress-related responses to alternations between repetitive physical work and cognitive tasks of different difficulties2019In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126Article in journal (Refereed)
    Abstract [en]

    This experimental study aimed to determine the extent to which a repetitive physical task alternatingwith a cognitive task (CT) influences stress responses and whether the CT difficulty is important. Fifteen women performed three sessions of 10 consecutive work bouts, each including a seven-minutere petitive physical task and a three-minute CT at either of three difficulty levels. Stress-related responses were assessed using heart rate variability, blood pressure, salivary alpha-amylase, salivary cortisol, perceived stress and cognitive performance.The alternating work did not result in any marked increase in perceived stress or changes in stressresponses. CT difficulty did not influence stress responses (all p>0.05), apart from alpha-amylase which was higher during the easiest CT (F= 5.34, p= 0.02). Thus, introducing cognitive work bouts into repetitive physical work did not result in increased levels of stress, suggesting this approach to be viable in job rotation.

  • 43.
    Nardi, Elena
    et al.
    School of Education and Lifelong Learning, University of East Anglia, Norwich, UK.
    Ryve, Andreas
    School of Education, Culture and Communication, Mälardalen University, Västerås, Sweden.
    Stadler, Erika
    Department of Mathematics and Science Education, Stockholm University, Stockholm, Sweden.
    Viirman, Olov
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics. Department of Mathematics, Karlstad University, Karlstad, Sweden.
    Commognitive analyses of the learning and teaching of mathematics at university level: The case of discursive shifts in the study of Calculus2014In: Research in Mathematics Education, ISSN 1479-4802, E-ISSN 1754-0178, Vol. 16, no 2, p. 182-198Article in journal (Refereed)
    Abstract [en]

    In this paper we outline the main tenets of the commognitive approach and we exemplify its application in studies that investigate the learning and teaching of mathematics at university level. Following an overview of such applications, we focus on three studies that explore fundamental discursive shifts often occurring in the early stages of studying Calculus. These shifts concern the lecturers' and students' communicative practices, routines of constructing mathematical objects and ways of resolving commognitive conflicts. We then propose that commognitive constructs such as subjectification can be deployed towards 'scaling-up' the hitherto fine-grained focus of commognitive analyses. Finally, we conclude with observing how the commognitive approach relates to constructs from other sociocultural approaches to research in university mathematics education, such as "legitimate peripheral participation" from the theory of Communities of Practice and "didactic contract" from the Theory of Didactic Situations. 

  • 44.
    Nyman, Rebecka
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science. 8604301708.
    Fotosyntesen: Att undervisa det abstrakta för elever i åk. 4-62019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien var att undersöka lärares upplevelser gällande undervisningen av fotosyntesen i grundskolans årskurs 4-6 med fokus på svårigheter och progression. I undersökningen deltog åtta lärare som undervisar i NO och materialet samlades in via semistrukturerade intervjuer. Lärarna lyfter fram tre typer av svårigheter: elevens svårigheter som till exempel att förstå gasbegreppet, lärarens svårigheter som att visualisera det abstrakta och svårigheter vilka gäller hinder i undervisningen som tidsbrist, ekonomiska begränsningar eller elevgruppen i sig. Undersökningen visar att lärare ofta använder sig av multimodala undervisningssätt, där fler än ett sinne stimuleras, de varierar mellan olika tekniker för att nå så många elever som möjligt. Lärarna anser att en varierande undervisning med olika tekniker som repeterar men sakta bygger på kunskaperna hos eleven även är det som ger det bästa resultatet för elevens förståelse (progression).  Att ge eleven vederläggande texter är en teknik som enligt tidigare forskning visat sig vara effektiv men var inte en teknik som lyftes av någon lärare i undersökningen. Resultaten indikerar att lärare behöver en tydligare plan för vad som ska läras ut när och till viss del hur, vilket inte bara skulle kunna underlätta progressionen utan även förebygga några av de svårigheter som finns med undervisningen om fotosyntesen.

  • 45.
    Sahlin, Matilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Så du menar att du har tagit tior, istället för femmor?: - En studie om laborativ matematikundervisning ur ett lärarperspektiv2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I dagens skola har det givits större plats till den laborativa matematikundervisningen för att minska den teoretiska tysta räkningen. Det här kommer studien att fördjupa sig igenom frågeställningarna:

     

    ·      Vilka laborativa material använder lärare i grundskolans yngre åldrar i matematikundervisningen inom addition och subtraktion i Gävleområdet?

    ·      Vilka upplevelser har lärare i Gävleområdet av det laborativa arbetssättet i matematikundervisningen? Och vad deras upplevelser beror på?

    ·      På vilket sätt kan en lektion med ett laborativt material inom området addition och subtraktion, skapa a-didaktiska-situationer?

     

    Två metoder kommer att användas för att samla in data för studien: två enkäter och en observation genom ett teoretiskt ramverk. Enkäterna visar vilka laborativa material som lärare använder i Gävleområdet, samt deras upplevelser kring materialet. Observationen är en fallstudie där eleverna får arbeta med laborativt material och resultatet visar att det laborativa materialet ökar elevernas kommunikation kring innehållet. Resultatet från undersökningarna stärks även av tidigare forskning som tyder på att laborativ undervisning har en positiv effekt på elevers kunskapsutveckling.

  • 46.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    On a Method of Solution to Dispersion Equations in Electromagnetics2019In: 2019 URSI Asia-Pacific Radio Science Conference (AP-RASC), New Dehli, 2019, article id 8738297Conference paper (Refereed)
    Abstract [en]

    A possible general approach to the analysis of dispersion equations (DEs) of electromagnetics is presented. The method takes into account the known explicit forms of DEs describing eigenoscillations and normal waves in layered structures and is based on the development of the notion of generalized cylindrical polynomials. The approach enables one to complete rigorous proofs of existence and determine domains of localization of the DE roots and validate iterative numerical solution techniques.

  • 47.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Trigonometric and cylindrical polynomials and their applications in electromagnetics2019In: Applicable Analysis, ISSN 0003-6811, E-ISSN 1563-504XArticle in journal (Refereed)
    Abstract [en]

    Development of the theory of trigonometric polynomials (TPs) is considered that involves generalization of the notion of TP and extension of the methods and results to cylindrical polynomials (CPs). On the basis of the proposed augmentation of TPs and CPs, a general approach is presented to the analysis of guided waves and resonances in electromagnetics and beyond. The method employs the known explicit forms of dispersion equations (DEs) describing eigenoscillations and normal waves in layered structures and is based on the development of the theory of generalized TPs and CPs performed in the study. The approach enables one to complete rigorous proofs of existence and determine domains of localization of the TP and CP zeros and the DE roots and validate iterative numerical solution techniques.

  • 48.
    Shestopalov, Yury
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Kuzmina, Ekaterina
    Moscow Technological University MIREA, Moscow, Russia.
    On Recent Findings in the Theory of Complex Waves in Open Metal-Dielectric Waveguides2018In: 2018 2ND URSI Atlantic Radio Science Meeting (AT-RASC), IEEE, 2018Conference paper (Refereed)
    Abstract [en]

    Theory of complex waves (see e.g. [1] and references therein) accumulated a big volume of results. However, its biggest drawback remains which brakes significantly the development of the theory: absence of rigorous proofs of the existence of complex waves. In this respect, studies of complex waves in open metal-dielectric waveguides has been essentially enhanced when two new families of symmetric (angle-independent) complex waves have been identified [2, 3] in a dielectric rod (DR) and Goubau line (GL) with homogeneous dielectric cover: surface complex waves occurring as perturbations of real surface waves caused by the presence of lossy dielectric, and pure complex waves which have no counterpart in the set of real waves. Existence of the latter family of complex waves has been shown using a special technique and the proof [3] of the existence of an infinite set of complex roots of the dispersion equation (DE) describing waves in DR and GL.

    In this work, a development of the analytical and numerical methods [2, 3] are considered for the analysis of the electromagnetic wave propagation in metal-dielectric waveguides with multi-layered dielectric filling. The first step constitutes extension of the results obtained for symmetric complex waves in DR and GLto the case of non-symmetric (angle-dependent) waves, and the second step, to multi-layered dielectric covers. Both steps are accomplished using specific forms of DEs obtained in [3]by construction analytical continuation of the functions involved in DEs to multi-sheet Riemann surfaces of the spectral parameter and applying appropriate generalization the techniques [4]forfinding complex roots of the DEs.

    Calculation ofnon-symmetric complex waves employs numerical solution of the DEs with the help of parameter differentiation in the complex domain using multi-parameter setting and analysis of implicit functions of several complex variables [5] and reduction [2, 3] to numerical solution of auxiliary Cauchy problems.

    1. A. S. Raevskiiand S. B. Raevskii, Complex Waves, Radiotekhnika, Moscow, 2010.

    2. E. Kuzmina and Y. Shestopalov, “Waves in a lossyGoubau line,”10th European Conf. on Antennas and Propagation (EuCAP), Davos, Switzerland, 2016, doi: 10.1109/EuCAP.2016.7481368.

    3. E. Kuzmina and Y. Shestopalov, “Complex waves in a dielectric rod and Goubau line,” 19th Int. Conf. on Electromagneticsin Advanced Applications (ICEAA), Verona, Italy, 2017, pp. 963-966, doi: 10.1109/ICEAA.2017.8065417.

    4. Y. Shestopalov, “Resonant states in waveguide transmission problems,”PIER B,64: pp.119-143, 2015, doi: 10.2528/PIERB15083001.

    5.Y. Shestopalov,“On unique solvability of multi-parameter waveguide inverse problems, ”19th Int. Conf. on Electromagnetics in Advanced Applications (ICEAA), Verona, Italy, 2017, pp. 372-376, doi: 10.1109/ICEAA.2017.8065253.

  • 49.
    Shestopalov, Yury
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Sheina, Elena
    M. V. Lomonosov Moscow State University, Moscow, Russia.
    Smirnov, Alexander
    M. V. Lomonosov Moscow State University, Moscow, Russia.
    Development of Numerical Techniques for Forward and Inverse Waveguide Scattering Problems2018In: 2018 2ND URSI Atlantic Radio Science Meeting (AT-RASC), IEEE, 2018Conference paper (Refereed)
    Abstract [en]

    Development of the methods and algorithms [1, 2] are considered for the numerical solution to the forward problem of the electromagnetic wave scattering by inhomogeneous dielectric inclusions in a waveguide of rectangular cross section and inverse problem of reconstructing parameters of the dielectric inclusions from the values of the transmission coefficient of the scattered electromagnetic wave. The codes are developed implementing an FDTD method that employs the PML-layer technique. Numerical modeling and simulations are performed for the analysis of the wave propagation in waveguides of rectangular cross section loaded with parallel-plane layered media (layered dielectric diaphragms) and such diaphragms containing cubic dielectric inclusions. Validation is carried out of the results of calculations using closed-form solution [3] to the canonical single-layer structure.

    Progress in analytical - numerical investigations of the solutions to the forward and inverse waveguide problems are largely based on a recent discovery [4] of the singularities and extrema in the complex domain of the transmission coefficient of layered dielectric diaphragms. In fact, the knowledge of the location of singularity and extrema sets of the scattering matrix allows one to justify correct determination of real or complex permittivity of each layer of the diaphragm by specifying domains in the complex plane where the transmission coefficientis one-to-one; that is, the domains that do not contain singularities and where unique permittivity reconstruction is therefore possible. Forthe forward problem of the scattering of a normal waveguide mode by a single-and three-layer diaphragms with a dielectric cube, it is shown [1, 2] that variation in the values of the transmission coefficient can be up to two orders of magnitude less than that of the permittivity of the inclusion. Taking into account this result and the presence of singularities, improvements are proposed of the numerical method, algorithms and codes implementing the calculations. The results of modeling and computations are validated by comparing with experimental and measurement data [3]. The requirements are formulated that should be imposed on the accuracy of computations and measurements necessary to reconstruct numerically permittivity of the inclusion from the amplitude and phase of the transmitted wave with the prescribed accuracy.

    1. E. Sheina, A. Smirnov,Y. Shestopalov,and M.Ufimtsev,“FDTD solution of reconstructing permittivity of a dielectric inclusion in a waveguide taking into account measurement inaccuracy,”Progress in Electromagnetics Research Symposium (PIERS),St Petersburg, Russia, 2017, pp. 3188-3195, doi:10.1109/PIERS.2017.8262306.

    2.E. Sheina, A. Smirnov, and Y. Shestopalov, “Influence of standing waves on the solution of the inverse problem ofreconstructing parameters of a dielectric inclusion in a waveguide,”URSI Int. Symposium on Electromagnetic Theory (EMTS), Espoo, Finland, 2016,pp. 643-646, doi:10.1109/URSI-EMTS.2016.7571479.

    3. Yu. G. Smirnov, Yu. V. Shestopalov, and E. D. Derevyanchuk, “Inverse problem method for complex permittivity reconstruction of layered media in a rectangular waveguide,”Physica Status Solidi(C), 11,5-6, 2014,pp. 969–974, doi:10.1002/pssc.201300697.

    4. Y. Shestopalov, “Resonant states in waveguide transmission problems,”PIER B,64: pp.119-143, 2015, doi: 10.2528/PIERB15083001.

  • 50.
    Shestopalov, Yury
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Smolkin, Eugene
    Department of Mathematics and Supercomputing, Penza State University, Penza, Russia.
    Snegur, Maxim
    Department of Mathematics and Supercomputing, Penza State University, Penza, Russi.
    New Propagation Regimes of TE Waves in a Waveguide filled with a Nonlinear Dielectric Metamaterial2019In: 2019 URSI Asia-Pacific Radio Science Conference (AP-RASC), New Dehli: IEEE, 2019, article id 8738241Conference paper (Refereed)
    Abstract [en]

    We consider propagation of surface TE waves in a circular metal-dielectric waveguide filled with nonlinear (Kerr nonlinearity) metamaterial medium. Analysis is reduced to solving a nonlinear transmission eigenvalue problem for an ordinary differential equation; eigenvalues of the problem correspond to propagation constants of the waveguide. For the numerical solution, a method is proposed based on solving an auxiliary Cauchy problem (a version of the shooting method). As a result of comprehensive numerical modeling, new propagation regimes are discovered.

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