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  • 4001.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Uppsala University, Department of Information Technology, Sweden.
    Mapping of roof types in orthophotos using feature descriptors2018In: International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM: Proceedings of the International Multidisciplinary Scientific GeoConference SGEM, 2018, Vol. 18, p. 285-291Conference paper (Refereed)
    Abstract [en]

    In the context of urban planning, it is very important to estimate the nature of the roof of every building and, in particular, to make the difference between flat roofs and gable ones. This analysis is necessary in seismically active areas. Also in the assessment of renewable energy projects such solar energy, the shape of roofs must be accurately retrieved. In order to perform this task automatically on a large scale, aerial photos provide a useful solution. The goal of this research project is the development of algorithm for accurate mapping of two different roof types in digital aerial images. The algorithm proposed in this paper includes several components: pre-processing step to reduce illumination differences of individual roof surfaces, statistical moments calculation and color indexing. Roof models are created and saved as masks with feature specific descriptors. Masks are then used to mark areas that contain elements of the different roof types (e.g. gable and hip). The final orthophoto visualize an accurate position of each of the roof types. The result is evaluated using precision recall method.

  • 4002.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Department of Information Technology, Uppsala University, Uppsala, Sweden.
    Segmentation of shadows and water bodies in high resolution images using ancillary data2016In: 16th International Multidisciplinary Scientific GeoConference SGEM 2016: SGEM2016 Conference Proceedings : Book 2, 2016, Vol. 1, p. 827-834Conference paper (Refereed)
    Abstract [en]

    High spatial resolution imagery is often affected by shadows, both in urban environments with large variations in surface elevation and in vegetated areas. It is a common bias in classification when waters and shadows are registered as the same area. The radiometric response for the shadowed regions should be restored prior to classification. To enable that, separate classes of non-shadowed regions and shadowed areas should be created. Previous work on water extraction using low/medium resolution images, mainly faced two difficulties. Firstly, it is difficult to obtain accurate position of water boundary and secondly, shadows of elevated objects e.g. buildings, bridges, towers and trees are a typical source of noise when facing water extraction in urban regions. In high resolution images the problem of separation water and shadows becomes more prominent since the small local variation of intensity values gives rise to misclassification. This paper proposes a robust method for separation of shadowed areas and water bodies in high spatial resolution imagery using hierarchical method on different scales combined with classification of PCA (Principal Component Analysis) bands, which reduces the effects of radiometric and spatial differences that is commonly associated with the pixel-based methods for multisource data fusion. The method uses ancillary data to aid in classification of shadows and waters. The proposed method includes three steps: segmentation, classification and postprocessing. To achieve robust segmentation, we apply the merging region with three features (PCA bands, NSVDI (Normalized Saturation-value Difference Index) and height data). NSVDI discriminates shadows and some water. In the second step we use hierarchic region based classification to identify water regions. After that step candidates for water pixels are verified by the LiDAR DEM data. As a last step we consider shape parameters such as compactness and symmetry to completely remove shadows.

  • 4003.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Time-space visualisation of Amur river channel changes due to flooding disaster2014In: Proceedings of the International Multidisciplinary Scientific GeoConference SGEM, 2014, Vol. 1:2, p. 873-882Conference paper (Refereed)
    Abstract [en]

    The analysis of flooding levels is a highly complex temporal and spatial assessment task that involves estimation of distances between references in geographical space as well as estimations of instances along the time-line that coincide with  given spatial locations. This work has an aim to interactively explore changes of Amur River boundaries caused by the severe flooding in September 2013. In our analysis of river bank changes we use satellite imagery (Landsat 7) to extract parts belonging to Amur River. We use imagery from that covers time interval July 2003 until February 2014. Image data is pre-processed using low level image processing techniques prior to visualization. Pre-processing has a purpose to extract information about the boundaries of the river, and to transform it into a vectorized format, suitable as inputs subsequent visualization. We develop visualization tools to explore the spatial and temporal relationship in the change of river banks. In particular the visualization shall allow for exploring specific geographic locations and their proximity to the river/floods at arbitrary times. We propose a time space visualization that emanates from edge detection, morphological operations and boundary statistics on Landsat 2D imagery in order to extract the borders of Amur River. For the visualization we use the time-space-cube metaphor. It is based on a 3D rectilinear context, where the 2D geographical coordinate system is extended with a time-axis pointing along the 3rd Cartesian axis. Such visualization facilitates analysis of the channel shape of Amur River and thus enabling for a conclusion regarding the defined problem. As a result we demonstrate our time-space visualization for river Amur and using some amount of geographical point data as a reference we suggest an adequate method of interpolation or imputation that can be employed to estimate value at a given location and time.   

  • 4004.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science. Uppsala University, Department of Information Technology, Sweden.
    Kautz, Marie-Loise
    Technische Universität, Dresden, Germany.
    Data source evaluation for shoreline deliniation applications2017In: International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM: Conference proceedings, 2017, Vol. 17, no 2-3, p. 849-858Conference paper (Refereed)
    Abstract [en]

    This paper proposes an evaluation of data acquired with various sensors and used in coastal water segmentation applications. Correct monitoring of coastal changes in dynamic coastal environments strongly depends on accurate and frequent detection of shoreline position. Automatic shoreline delineation methods are preferable, especially in terms of time, cost, labor intensiveness and difficulties of in-situ measurements. Two main issues have been encountered within this application field, the quality of data and the segmentation algorithms. In this work, potential benefits of various data sources including optical and active sensors for extraction of shorelines have been investigated. The goal with shoreline detection from digital data sources is to obtain information as efficiently as possible and as reliably as necessary. Starting with that observation the paper discusses the effectiveness of coastal information extraction provided different data sources. This question is especially important to address since we observe a fast development of high spatial resolution data acquisition. There are many of segmentation algorithms described in the field of image processing and yet there is currently no single theory or method, no universal segmentation framework, that can be applied on all images to precisely and robustly extract shorelines. Nether there is a uniform standard for the assessment of segmentation results, and this process still largely relies on visual analysis and personal judgment. Out of myriads of image segmentation algorithms, we chose the most frequently and successfully applied within the application field and considering the data sources. In optical sensor data cases, the most frequently used methods are NDWI (Normalized Difference Water Index) and thresholding techniques. We do not aim to create yet another method to segment out the particular objects from remotely sensed data and then tailor it to work efficiently on that data set. Instead, we evaluate the data quality regarding the given application field. The case study is carried out on a 10 km coastal stretch facing the Baltic Sea (Sweden) and belonging to the Municipality of Gävle. In citu measurements were acquired to evaluate the extracted coastal lines and comparisons with reference were performed based on the average mean distance. A conclusion is done regarding the most reliable data source for this particular application of shoreline delineation.

  • 4005.
    Åhlén, Julia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Liu, Fei
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Evaluation of the Automatic methods for Building Extraction2014In: International Journal Of Computers and Communications, ISSN 2074-1294, Vol. 8, p. 171-176Article in journal (Refereed)
    Abstract [en]

    Recognition of buildings is not a trivial task, yet highly demanded in many applications including augmented reality for mobile phones. Recognition rate can be increased significantly if building façade extraction will take place prior to the recognitionprocess. It is also a challenging task since eachbuilding can be viewed from different angles or under differentlighting conditions. Natural situation outdoor is when buildings are occluded by trees, street signs and other objects. This interferes for successful building façade recognition. In this paper we evaluate the knowledge based approach  to automatically segment out the whole buildingfaçade or major parts of thefaçade. This automatic building detection algorithm is then evaluated against other segmentation methods such as SIFT and vanishing point approach. This work contains two main steps: segmentation of building façades region using two different approaches and evaluation of the methods using database of reference features. Building recognition model (BRM) includes evaluation step that uses Chamfer metrics. BMR is then compared to vanishing points segmentation. In the evaluation mode, comparison of these two different segmentation methods is done using the data from ZuBuD.Reference matching is also done using Scale Invariant Feature Transform. Theresults show that the recognition rate is satisfactory for the BMR model and there is no need to extract the whole building façade for the successful recognition.

  • 4006.
    Åhman, Matilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Luftburen värme med ett centralaggregat i flerbostadshus2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The fact that the global warming is a major probelm in today´s society is no news and the climate change continues to take place at a very high rate. In order to create a sustainable society change requires where the potential is on energy efficiency and increased use of renewable energy. Energy efficiency can be changes in behavior, additional insulation of buildings or switching to more energy efficient installations. From a thermal comfort- and energyperspective today there are diffrent oppinions about airborne heat if it is a good heating system.

    This thesis is made for Ramböll, a consultant firm which focuse on technology and construction of society. The purpose of the study is to investigate whether a radiator system in an appartent buildning can be replaced by an airborne heating system with a central unit to get a more cost efficient system.

    This study is based on calculations for transmissions, airflow and directed operative temperature for the current building. Based on these data the ventilationsystem has been constructed and dimensioned. Also a proposal for the regulation of the indoor temperature for the system has been produced and also a economic comparison between the airborne heating system and the radiator heating system has been made.

    The resaults of the study shows that for the apartment building the airborne heating system is a cheaper alternative compared to the radiator system, based on prices of materials and work. The study shows that the thermal comfort with a airborne heating system is not affected in a bad way by the directed operative temparature in the occupied zone. Also larger ducts will be needed with airborne hating, which will require bigger and more space consuming shaft. The regulation of the indoor temperature is going to be with VAV-throttle in every appartmen, which means that the regulation can be done in each appartment but not in every single room. 

  • 4007.
    Åhr, Simon
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Framtagning av ett multiplexerat datainsamlingssystem för mätning av små elektriska strömmar2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
  • 4008.
    Åhrman, Martin
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Elevers syn på hållbar utveckling2010Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 4009.
    Åkerlind, Sofia
    University of Gävle, Faculty of Engineering and Sustainable Development. University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Matematik i förskolan: Pedagogers uppfattningar och arbete med ämnet i verksamheten2010Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med uppsatsen är att ta reda på vad pedagoger på fyra förskolor i en mellansvensk stad har för uppfattningar om matematik i förskolan och hur de själva anser att de arbetar med ämnet i verksamheten. Undersökningen bygger på en enkät där pedagogerna fått beskriva vad de anser att matematik i förskolan är samt hur de arbetar med ämnet i verksamheten.

    I resultatet kan man bland annat urskilja att pedagogerna anser att matematik i förskolan till stor del handlar om att lära barnen vissa grundläggande matematiska färdigheter såsom jämförelse och mätning, sortering, former och antal. Pedagogerna beskriver att de har ett ansvar att göra matematiken lustfylld och intressant samt att den till största del sker i den dagliga verksamheten och inte vid planerade tillfällen. I verksamheten använder man sig av exempelvis sagor, pussel och spel. Man arbetar dessutom med sorteringsövningar och sånger och ramsor för att öka barnens matematiska förmåga.

  • 4010.
    Åkerström, Johan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Alsade, Noor
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Nudging för att minska köttkonsumtion: En studie för att förändra studenters beteende2019Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The purpose of the study is to investigate whether nudging is an effective method for changing behavior among students at Gävle University. The study will investigate whether two nudging methods (information campaign and nudge) can change the students' behavior, while comparing which method gives better effect to changing behavior and reducing meat consumption. First, a literature study will investigate wheater meat affects the climate and how much greenhouse gas emissions from meat can potentially be reduced by students at the Högskolan i Gävle using information campaigns and nudge. To further answer the purpose, two surveys and two nudging methods have been conducted at the Högskolan i Gävle. The first survey study was conducted to measure how much meat and the type of meat consumed by students, then two nudging methods have been used in order to change behavior and reduce or change the choice of meat among students. The second survey study was conducted to investigate whether the campaigns have changed behavior and reduced or changed the choice of meat among students. Results show that nudging has had an effect and behavior has changed. Nudge has reduced meat consumption and carbon dioxide emissions. The survey study contained 6 questions where only question 1 turned out to be significant and can be linked to nudge [KH1] in the interaction, information campaign is a contributing factor to this change.

     

  • 4011.
    Åkesson, Ida Linnéa
    University of Gävle, Faculty of Engineering and Sustainable Development. University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Värmeförsörjning av ett framtida industriområde: En utredning och utformning av ett hållbart energisystem2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 4012.
    Åsander, Henrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Tillvaratagande av värmeenergi ur gråvatten med värmepump i flerbostadshus2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Large amounts of energy leave homes with wastewater without any effort to return the heated water's thermal energy back to the building. With increased thermal envelope improvements of a traditional nature to meet the nearly zero-energy requirements for residential buildings that will come into effect by the end of 2020, energy losses in buildings can increasingly be allocated to the wastewater leaving the building.

    The aim of this work is to investigate whether significant energy savings in the mentioned area can be obtained, as well as to assess the economic opportunities and prospects for utilizing heat energy from grey water from multi-residential buildings connected to district heating networks with the help of a heat pump. And by that show which factors are shown to influence the operational savings and how sensitive the results are in relation to a selection of these factors. The work consists of and has been carried out in two parts: a literature study and a calculation study.

    Household wastewater can be divided into grey and black water. Grey water is the water that comes from bath, dishes and laundry and black water is the water that is flushed out of the toilets. Separated flows reveal the possibility of utilizing thermal energy directly from grey water, which is also the warmer, volume largest and more manageable fraction, both from a water purification and heat recovery standpoint. Studies on source separated systems show a wide range of benefits, largely by keeping household wastewater separated, such as increased resource efficiency of nitrogen and phosphorus at the wastewater treatment plants. The contamination of heat exchanger surfaces, especially biofilm, poses a challenge when wastewater is used as a heat source and is something that has to be taken into account even when using grey water as a heat source.

    The result of the calculations of an individual case with preheating of domestic hot water, given a series of assumptions, resulted in operational cost savings of approximately SEK 31,000 per year and a present value of these annual savings over 20 years of approximately SEK 355,000. Energy savings amounted to approximately 63,000 kWh per year, which means a reduction of the total need for purchased energy for domestic hot water production by 67 % with an assumption of a final domestic hot water temperature of 55 °C. The sensitivity analysis shows that crucial parameters in the calculation study such as electrical and district heating price, heat pump life and discount rate entail relatively large changes in profit if allowed to vary.

    It is obvious that there are large amounts of energy to potentially recycle. It is also obvious that difficulties cause grey water as a source of heat not be treated easily because, among other things, the long-term development of household water use and high pollution rates are factors that must be considered in addition to the factors brought up in the sensitivity analysis.

    District heating and heat pump combined imply a higher investment than a single heating system, but at the same time is something that can be seen as a tool for utilizing the assumed increasing energy price variations that an increasing proportion of intermittent renewable power generation implies simply by varying heating configuration with changes in energy prices and finding the optimal share. For a property owner, it would at this point be favorable to be able to choose what the cheapest option is currently.

  • 4013.
    Åsberg, Anton
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering.
    Länge leve kläderna: Förslag på metoder för att minska textilkonsumtionens klimatpåverkan2019Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [sv]

    Det här är ett arbete som behandlar textilindustrins klimatpåverkan i allmänhet och klädesindustrins klimatpåverkan i synnerhet. I arbetet undersöks på vilka sätt man kan engagera människor till en långsiktig förändring med fokus på att aktivt förlänga kläders livslängd i Sverige. För att förstå och få möjligheten att greppa den negativa påverkan som textilindustrin har på klimatet redogörs en grundlig litteraturstudie som undersöker kläders livscykelanalys, textilindustrins utsläpp av kemikalier och metoder för att positivt påverka och även en stor del som tar upp psykologiska barriärer. 

    I mitten av arbetet presenteras ett experiment som under en vecka handlade om att reparera privatpersoners jeans. Experimentet tillsammans med mötena med människorna vars jeans jag lagade kom att spela en stor roll för arbetet och resultatet.

     I experimentet presenteras ett förslag på hur man med relativt små medel kan avsevärt minska konsumtionen och klimatpåverkan i form av en tjänst eller system som tillgodoser behovet av att reparera jeans. Tjänsten bygger på tjänstefierad cirkulär ekonomi och förslag på hur det kan implementeras i jeansens livscykel redovisas. Den designade tjänsten i fråga testas i verkligheten och genererar ett resultat som påvisar goda möjligheter till förbättrad ekologisk, ekonomisk och social hållbarhet. 71 par jeans lagas under en veckas tid, vilket sparar 1 000 000 liter vatten jämfört med om nya jeans köpts istället för lagats. 

  • 4014.
    Åsberg, Philip
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Bohlins, Pontus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Tidig detektering av skogsbränder med hjälp av högupplöst data: Automatisk identifiering med hjälp av bildbehandling2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    It is very difficult to discover forest fires in an early stage which can lead to devastat-ing consequences. Today, 30% of the total carbon dioxide that is released in the at-mosphere comes from forest fires. Thousands of human beings and animals are killed or forced to leave their homes every year. There are a variety of techniques today that is being used for discovering forest fires but whom lack in accuracy or has problems with a large amount of false alarms. This paper is an experimental study to try to solve this issue. The proposed method in this paper could be applied on UAV (Unmanned Arial Vehicles). This study will focus on identifying smoke regions from forest fires and removing fog objects which has similar characteristics as smoke. Two algorithms are tested, SDA (Statistical distributions algorithm) and KBA (Knowledge-based identification algorithm). The SDA uses statistic distribution al-gorithm where smoke and fogs characteristics are identified. The second algorithm, KBA, is a knowledge-based algorithm, where the shape, area and edges of the smoke’s characteristics are applied. The algorithm showed a 90 % accuracy for find-ing smoke in images with a false alarm rate of 20 % in images of fog.

  • 4015.
    Åshage, Anna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Ekosystemstödjande och multifunktionella växtval i urban miljö: En fallstudie med utgångspunkt i Nacka stadsbildning2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study has investigated how urban vegetation can be used in a multifunctional way to support ecosystem services in urban environments. Nacka municipality is in the start-up phase of building what is to become Nacka city. This provides a unique possibility to study and analyse what role the vegetation play in making the city a healthy living environment and how it needs to be adapted in order to be resilient against changing climate conditions and how the effects of those changes can be regulated. The study further investigates how airborne pollution, caused by urbanization processes, can be regulated or reduced by vegetation or species selection. Methods used in this study were a combination of qualitative interviews and literature studies, seeking to answer the questions: Which specific ecosystem functions are needed in the urban environment and which aspects will influence the ecosystems ability to deliver the functions in demand? And which plant species have the right mechanisms needed to deliver those functions? These questions have been studied and analysed in a local based context where the local conditions ands site specific needs of Nacka define criteria for plant selection. Based on those criteria, a plant list is presented that seeks to find synergies and effectiveness in plant selection with the aim to find plants that support and/or produce multiple ecosystem functions. 

  • 4016.
    Åström, Frida
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energieffektiviseringsanalys av ventilationssystemet för ett kraftvärmeverk: En fältstudie utförd i samarbete med Bomhus energi AB och ABB2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbeta kommer att utreda vilka det vanligaste energiförlusterna för ett kraftvärmeverk är, med fördjupning på förlusterna i deras ventilationssystem.  Kraftvärmeverket som har analyserats i detta arbete är Bomhus energi AB (BEAB) kraftvärmeverk och utredningen har skett i samråd med ABB Energy Efficiency team.    

    Världens energianvändning kan delas in i tre sektorer: industri, transport samt bostad- och servicesektorn. Industrisektorn kan sedan delas in i flera sektorer där massa och pappersindustrin står för majoriteten av energianvändningen i Sverige. Industrisektorn står för ca 64% utav världens el-energiförbrukning. Detta gör att det finns stort intresse i att se över de komponenter som har hög elförbrukning.     

    Fokuset har i detta arbete varit på ventilationssystemet och dess fläktrift. För att få information om vart det kan finnas komponenter som brukar mycket el så har styrsystemets loggar setts över. Besparingspotential har då identifierats i att installera frekvensomriktare till aggregatens fläktar istället för att använda den befintliga spjällregleringen. ABB har tidigare funnit besparingspotential i pumpdrifter för kraftvärmeverk och är därför nu intresserade av att se om det finns någon besparingspotential i ventilationssystemet.

    BEABs ventilation är uppdelad på process och allmänventilation, och genomlysning utav ventilationssystemet är i detta arbete begränsat till allmänventilationen i pannhuset. Detta då processventilationen anses vara korrekt dimensionerat.

    För att få insikt i hur energieffektivisering utav ventilationssystem kan gå tillväga har olika vetenskapliga artiklar rörande ämnet valts ut och analyserats. Som systemet är uppbyggt så sker regleringen utav ventilationen med spjällreglering. Spjällreglering innebär att fläktarna går på konstant flöde och för att uppnå önskad temperatur och tryck i byggnaden så sitter det tryckreglerande spjäll på taket som släpper ut luft ur byggnaden. Denna typ av styrning är inte särskilt energieffektiv, vilket har motiverat detta arbete till att rikta in sig på frekvensomriktare till aggregaten och hur mycket energi som då skulle kunna sparas.  För att få fram besparingspotentialen har hänsyn tagits till aggregatens: nominella volymflöde, fläktverkningsgrad, transmissionsverkningsgrad, flödesreglering, motoreffekt, motorns verkningsgradsklass, matningsspänning, fläkttyp, pumphjulstyp, varaktighetskurva, årgångstid, energipris samt multiplikatorn för Co2-utsläpp. Data har sedan matats in i ABB Energy Save kalkylatorn som då har tagit fram hur mycket energi och pengar som skulle kunna sparas genom att installera en frekvensomriktare.  Om de frekvensomriktare som då har tagits fram för de olika aggregaten skulle installeras så skulle uppskattningsvis ca 67 000 kr/år kunna sparas för kraftvärmeverket. 

  • 4017.
    Öberg, Karin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Det behövs ett nytt verktyg för att reparera bristande baskunskaper i matematik: En studie om Elevate My Math´s effekter hos svensla gymnasieelever2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Mätningar av kunskaperna inom matematik hos svenska elever har under en längre tid visat på en nedåtgående trend. Samtidigt läser vi dagligen om den svenska lärarkårens höga arbetsbelastning. Syftet med det här examensarbetet är att undersöka en hållbar lösning, som både vänder den nedåtgående kunskapstrenden hos eleverna och dessutom underlättar lärarnas arbete. I Examensarbetet undersöks elevernas upplevelser samt kunskapsutveckling då de  arbetar med det digitala verktyget Elevate My Math.

    Undersökningen, som är både kvantitativ och kvalitativ görs i en ekonomiklass där halva klassen får arbeta med Elevate My Math och den andra halvan får jobba med ett material som vanligtvis används inom undervisningen. Resultaten visar att eleverna upplevelse av att arbeta med Elevate My Math är mycket positiv. Samtidigt visar resultatet att vidare forskning behövs för att säkerställa elevernas kunskapsutveckling vid användandet av Elevate My Math.

  • 4018.
    Öberg, Kristofer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Bevisvärdering i brottmål: Går det tillämpa beslutsanalytiska metoder?2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I detta arbete behandlas de grundläggande elementen i en brottmålsprocess med särskilt fokus på hur själva bevisvärderingen går till, särskilt då DNA-bevisning ingår i materialet. Dels beskrivs de vanligast förekommande teorierna och vad som sagts om dessa i doktrinen, dels belyses utvalda rättsfall för att visa hur det hela faktiskt fungerar i praktiken. Problematiken kretsar främst kring hur en domstol kommer fram till att ett visst faktums existens är ställt utom rimligt tvivel. Texten föreslår att de nuvarande metoderna för bevisvärdering bör kompletteras med metoder som utvecklats av besluts-, risk- och policyanalysvetare. Mer specifikt föreslås att domstolar i större utsträckning bör använda metoder så som Bayes teorem för att anpassa sina sannolikhetsuppskattningar då nya bevis förs fram i en process.

  • 4019.
    Öberg, Nathalieé
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Flera gånger om: ett multiplikationsspel testat i årskurs 22017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Examensarbetet har haft till syfte att undersöka om ett undervisningsmaterial, i form av ett multiplikationsspel, kan ligga till grund för att elever i årskurs 2 får ett ökat intresse att lära sig automatisera multiplikationstabell 2-5, samt multiplikationstabell 10. Genomförandet har inneburit att eleverna i en årskurs tvåa har spelat multiplikationsspelet under en sju veckors period. Under denna sju veckors period har eleverna gjort tre multiplikationstest, samt en elevenkät, som har sammanställts tillsammans med en lärarenkät under resultadelen. Resultaten visar att majoriteten av eleverna har förbättrat sitt resultat på multiplikationstesten under denna sju veckors period. Eleverna anser att det har varit roligt att spela multiplikationsspelet och läraren ser värdet av att fortsätta använda multiplikationsspelet.

  • 4020.
    Ödeving, Sandra
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Geometri i förskolan2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 4021.
    Ödman, Sara
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Hur påverkas barn av stress och hur kan stress motverkas i förskolan?2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med den här uppsatsen var att undersöka om det förekommer stress bland barnen i förskolan, hur den i så fall yttrar sig samt hur personalen vid förskolorna jobbar för att motverka eventuell stress bland barnen. Muntliga intervjuer användes som undersöknings metod med diktafon som hjälpmedel. Åtta förskollärare har blivit intervjuade och intervjuerna har utförts i två olika kommuner. Resultatet visade att det förekommer många olika tecken på stress bland barnen och att både pedagoger och föräldrar till stor del bidrar till stressen.

  • 4022.
    Ögren, Malin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Cykla i stadsmiljö: “Vinsten för individen av att cykla”2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Gävle municipality has a goal to increase cycling in Gävle. In the year 2025, the proportion of journeys less than four kilometers should be at 60%, a survey from 2012 showed that the proportion were only 24% (Atterbrand et al, 2012). According to the same survey, it was found that the municipality of Gävle will not achieve their goals about the proportion of short trips undertaken by bicycle since the number has not increased since 2006 (Indebetou et al, 2012).

    The essay aims to develop a concept that will encourage more people to choose the bicycle over other means of transport. The main goal is to find out how the interest in cycling in urban environments can be increased.

    The work has been limited to focusing to a local level, but the idea is that the results can be used to create similar products to all urban environments.

    Methods that have been used to get to the final result are interviews with individuals and with people working for the municipality of Gävle. The work also include a study of different scientific articles, an analysis to decide functions of the resulting concept and market research to determent what would be necessary to the results.

    For the research, official material from municipality of Gävle is used, as well as scientific articles and interviews. The facts are used to confirm reasons why people should choose to bike over other modes of transport as well as to show that Gävle has potential as a cycling city.

    The facts that are mentioned in the research are later on used to make different design proposals. Based on the interviews made, three bigger needs are presented as a way to select a design proposal to develop further. The result is presented at the end in the form of an app to smartphones.

    The appearance and features for the app that has been produced occurred after making a market research where two apps for smartphones were investigated, and also a feature to cyclists who the municipality of Gävle offers via their website to offer a custom wayfinding just for cyclists. The apps that were investigated is called RunKeeper and Google Maps. RunKeeper is a motivational app to increase interest in the exercise. Google Maps is an app that uses GPS to give directions for motorists, cyclists and pedestrians.

    The market investigation provided the basis for the final app dubbed Cyclum. Cyculm give tips on places to bike to show bike lanes in the city and can offer the cyclist wayfinding between two points that the user specifies. By using Cyclum cyclist can collect statistics about their bicycle use, a way to motivate to bike more.

  • 4023.
    Öhman, Johanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics. 19881121-1542.
    Lärares syn och attityd på användandet av digitala verktyg inom matematikämnet2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 4024.
    Öhman, Rasmus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energikartläggning av lokaler och processer i hyresfastigheten Sörby Urfjäll 37:32013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna uppsatts är att utreda energianvändningen i fastigheten Sörby Urfjäll 37:3 och samman ställa en energibalans.

    Mätningar gjordes på elanvändning, av temperaturer i ventilationskanaler och temperatur loggning gjordes i fastigheten. Under platsbesöken undersöktes användningen av maskiner, antalet människor som vistas i de olika delarna av fastigheten samt att maskiner, kylskåp, datorer och lampor räknades och eleffekten på dessa registrerades.

    Utifrån mätningar, statistik och observationer beräknades temperaturverkningsgrader ut på ventilationssystemen, värmetillskott och värmeförluster beräknades. Med utgångspunkt i beräkningar och statistik sammanställdes en energibalans.

    Åtgärder har utifrån de resultat som uppkom under arbetets gång för att effektivisera fastighetens energianvändning tagits fram. Åtgärdernas kostnader och hur invecklade de är varierar från att täta springor och rengöra fönster till att byta ut stora ventilationssystem.

  • 4025.
    Öholm, Frida
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Utredning av snödeponi med konstruerad våtmark: Undersökning av nya indikatorer och rutiner till kontrollprogram för Gävle kommun2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The study deals with the disposal of snow inGavle, and with systems for handling the masses of snow. The disposal of snow may fall within the classification of environmentally hazardous activities. One reason for this classification is the snow's ability to accumulate contaminants. The purpose of the study is that based on the high-profileproblem areas at the facilityfor snowprovide a basis for possible areas of improvement for the existing framework for the management of the facility.Since the facilityin this study has been deemed environmentally hazardous activities are a number of requirements that the facility should not constitute a nuisance to humans and the environment. Requirements include procedures for a structured approach to self-regulation. In this case there is an established inspection program to perform thecontrols. The monitoring program has contributed to insecurity in the municipality, when it has not been considered include facilityfor snowsactivity. With the examination of the existing control program has been considered in this study to be the most compatible with facilityfor snow. However, there are procedures in the control program should be reviewed and adjusted or even removed from the program.Therefore, a further investigation on what points in the program can be eliminated.Based on previously conducted water sampling, carried out by authorized consultants, and hasanalyzed the results compiled. There, among other things, revealed shortcomings with sampling designs. They have not been conducted according to the established inspection program and at times has been sampling absent entirely. Despite this, no higher concentrations of pollutants found for the melt water in comparison with the general guidelines. Therefore, routine surface water sampling questioned, it generally needs to be performed according to the prescribed in the control program.New indicators for the analysis of surface water havebeen produced as suggestions for future sampling. They have been implemented by investigating which substances have been found in highest concentration in the compilation of the sampling results, in which the metals copper, zinc and lead are the most abundant. Since these substances, together with suspended substances were found to be most detectable, these substances can be important indicators continue to evaluate. Survey has also been carried out on the basis of guidelines and standard levels for surface water, and it resulted in indicators chromium, nickel, phosphorus, nitrogen and PAHs were added.These substances not examined in the current situation, therefore, there may be a need to perform a comprehensive sampling. It can be implemented to determine which substances may be present in addition to what is already checked during sampling.

  • 4026.
    Öholm, Olivia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Reducering av ställtider2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    För att vara konkurrenskraftig i dagens globaliserade företagsklimat krävs kostnadseffektiva lösningar som gör det möjligt för företag att möta kundernas krav gällande såväl kvalitet som pris och förmåga att leverera enligt överrenskommelse. Gevalia, ett producerande företag i Gävle, har problem med långa ställtider som markant drar ner deras effektivitet. En universell vedertagen metod för att minska ställtider är SMED, Single minute exchange of die, som anses kunna göras kompatibel i alla typer av industrier.

     

    Syftet med detta examensarbete var således att undersöka orsakerna bakom de långa ställtiderna samt hur dessa kan minskas. Vidare skulle en analysstruktur för ställtidsreduktion skapas.  För att uppnå syftet har intervjuer och observationer gjorts på Gevalia, samt en litteraturstudie kring berörda områden.

     

    Analysstrukturen som skapades är inspirerad av SMED och PDCA-cykeln. Strukturen innefattar även andra metoder som bland annat 5 Why och 5S, samt tar hänsyn till det mänskliga beteendet. Strukturen består av fem steg:

    1. Kartlägg nuläget
    2. Analysera
    3. Skapa förbättringsförslag
    4. Implementera
    5. Utvärdera och återkoppla

     

    Denna struktur användes sedan för att komma fram till förbättringsförslag. Dessa förbättringsförslag blev:

    • Skapa en fixerad utgångspunkt
    • Skapa ett omställningsschema som innefattar hela omställningsprocessen
    • Utbilda och motivera personalen så de gör som det nya tillvägagångssättet säger.

     

    Dessa förbättringsförslag kommer efter examensarbetet tillämpas hos Gevalia.

  • 4027.
    Öhrn, Henrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    NoSQL-databaser och utnyttjandet av en grafdatabas i ett transportnätverk2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den allmänna kunskapen om NoSQL-databaser är begränsad. Den här uppsatsen koncentrerar sig på att sammanställa egenskaper och information om för- och nackdelar som rör dessa databastyper samt relationsdatabaser i en undersökning. Uppsatsen belyser även användningsområden för de olika databastyperna och i en fallstudie testas en grafdatabas förmåga att representera och utföra sökningar av data från ett järnvägsspårnät. Problemområdena undersöktes genom att samla information om olika typer av databaser från artiklar och böcker. Tillämpningsfallet i fallstudien implementerades och testades i en grafdatabas. Resultatet av undersökningen visade att NoSQL-databaser är ett intressant alternativ i vissa fall men att mycket hänsyn måste tas innan man väljer vilken typ av databas som är mest lämpad i den specifika tillämpningen. Resultatet av fallstudien visar att en grafdatabas är särdeles lämpad för att representera och utföra operationer på ett transportnätverk. Detta till stora delar beroende på dess förmåga att representera kopplingarna i ett transportnätverk och i form av de operationerna som finns i grafteorin och som grafmodellen erbjuder.Nyckelord: nosql, relationsdatabas, nyckel/värde-databas, kolumndatabas, objektdatabas, dokumentdatabas, grafdatabas, järnvägsnätverk, transportnätverk

  • 4028.
    Öhrn, Tobias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Quartzene i betong: Hur påverkas hållfastheten?2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete undersöker hur Quartzene® som tillsatsmaterial påverkar hållfastheten hos betong. Arbetet sker i samarbete med företaget Svenska Aerogel AB som också äger patent på Quartzene®. Ämnet har vissa likheter med andra tillsatsmaterial som används i Sverige. Quartzene® har dock ett kartlagt innehåll vilket är en fördel jämfört med de andra tillsatsmaterialen som måste analyseras innan användning.

    Syftet är att prova hur Quartzene® i olika doser och diverse sammansättningar påverkar hållfastheten hos betong. Litteraturstudier har legat till grund för de praktiska provningarna och analyserna av givna resultat. Arbetet gjordes i ett byggtekniskt laboratorium med utrustning för böjdrag- och tryckhållfasthetstester, våg, elektriskt skjutmått mm. Prover gjordes på 7 och 28 dygn gamla betongprismor. Resultatet som presenteras och analyseras i rapporten visar på att Quartzene® förändrar hållfastheten. Att byta ut en del av cementen mot Quartzene® har ingen positiv inverkan på varken 7 dygn eller 28 dygnshållfastheten. Oklart hur det skulle se ut efter längre tid t ex ett år.

    Quartzene® blandades i som pasta i vissa betongrecept och som pulver i andra.

    Konsistensen på betongen blev torrare när Quartzene®pasta blandades i. Trots att pastan innehåller 85 % vatten blev alltså blandningen fast. Den blev dessutom än mer fast efter bara några minuter eftersom pastan stelnar av sig själv. Vattnet i pastan tycktes inte vilja bidra med lägre viskositet. När Quartzene® i pulverform blandades i, blev betongmassan däremot mycket lätt att arbeta med. Det går att dra slutsatser att Quartzene® i pulverform är bättre för hållfastheten än vad Quartzene®pasta är. Den ger ungefär 5 MPa högre tryckhållfasthet. Om 5 MPa skulle adderas till resultaten för betongen som blandades med Quartzene®pasta skulle den ge högre hållfasthet än den som betong var utan Quartzene®.

    I de recepten med mycket Quartzene® var det en mer positiv utveckling mellan 7 och 28 dygn. Därför hade varit mycket intressant att se hur det skulle ha sett ut efter 90 och 365 dagar.

  • 4029.
    Ölander, Jonas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Löfqvist, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Utveckling av stödverktyg för livsmedels- & miljöinspektörer2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Gävle kommuns miljö- och livsmedelsinspektörer utför inspektioner hos ca 660 företag och organisationer inom Gävle kommun. Information om organisationer och inspektioner hanteras av ett ärendehanteringssystem. Detta ärendehanteringssystem är inte anpassat för sättet inspektörerna arbetar, vilket gör att de tvingas komplettera viss funktionalitet med ett Exceldokument. Detta Exceldokument löser vissa problem men fungerar inte bra. Detta arbetes syfte och mål är att utveckla en grund till en webbapplikation, i beta-stadiet, vilket ska kunna ersätta det Exceldokument inspektörerna arbetar med och effektivisera deras arbete genom att göra den verksamhetsanpassad. Arbetet resulterade i en webbapplikation vilket effektiviserar inspektörernas arbetssätt. Webbapplikationen är utformad med responsivt gränssnitt. Omdömet av webbapplikationen var positivt och visade på ett förbättrat arbetssätt.

  • 4030.
    ölander, kristian
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Industrial design.
    Produktutveckling för catch and release fiske: Ett redskap som underlättar landning av fisk2018Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
  • 4031.
    Öqvist, Jens
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Jonason, Kristoffer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Interna processer: Modell för ett effektivt returstålsflöde2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The last decade has created an increasing pressure on companies to decrease their impact on the environment and to increase their effectiveness of recycling the company’s resources, especially for the steel industry. Companies have also started to realize the economic aspects of an effective internal reverse logistics. In the past the value of an effective internal reverse logistic was something that companies tend to underestimate and there are few academic studies done in this area.

     

    The purpose of this essay has been to identify key factors to create an effective in plant storage, transport, sorting and handling of returned steel. From these factors a generalized model for creating an effective return steel flow will be developed. The model will then be adjusted to fit a case company, which in this case is Sandvik Materials Technology (SMT) on Sandvik.

     

    The purpose is answered by detailed studies of the literature in the subject combined with interviews and observations on SMT. Through this the key factors have been identified and a model has been developed. The factors that were seen as most crucial were sorting, tied up capital, transport cost and handling cost. These factors have a strong connection between each other and it is important to strike a balance.

     

    By the investigation carried out on SMT it is clear that sorting is the essential factor on the case company, and have the biggest impact on the effectiveness of the returned steel flow. Without functioning sorting there will be a large increase in the quality defect costs. Another factor that was considered important is the number of storage places, where a decrease in the storage places would reduce the tied up capital.

  • 4032.
    Örn, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Linander, Fredric
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Konstruktion av testbänk för karaktärisering2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 4033.
    Örnblom, Anna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Strategier vid problemlösning i matematik: Lärares arbete med problemlösning i matematik i de lägre årskurserna2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Denna studie har genomförts för att undersöka om och hur lärare i de lägre årskurserna arbetar med och lär ut problemlösning i matematik. Metoder som använts för att undersöka detta är enkät och intervju. Totalt har 16 lärare svarat på enkäten och 4 lärare har deltagit i en kvalitativ intervju. Resultatet redovisar att alla deltagande lärare arbetar aktivt med problemlösning i matematik. De använder olika arbetssätt, strategier och lösningsstrategier i sitt arbete med att undervisa i problemlösning.

  • 4034.
    Östansjö, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Utveckling av nytt Radiofarmakaregister i Java2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Avdelningen Nuklearmedicin på Gävle sjukhus har problem med att deras befintliga ”Radiofarmakaregister” inte fungerar på Windows 7, som de håller på att uppgradera till. Därför har Gävle sjukhus utlyst ett examensarbete med syftet att lösa problemet med att programmet inte fungerar på Windows 7. Det här projektet gick ut på att utveckla ett nytt program från grunden med de krav sjukhuset ställde. Det nya programmet utvecklades i programmeringsspråket Java. Vid projektets slut uppfylldes de krav som ställdes på projektet

  • 4035.
    Östberg, Evelina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Krummeltåget: ett designprojekt om hur man kan arbeta praktiskt med genus i förskolan2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Redan i förskoleåldern lär sig barn att anpassa sitt beteende till de könsroller som de blivit tilldelade av samhället. Enligt Anette Hellman (Kan Batman vara rosa? Förhandlingar om pojkighet och normalitet på en förskola, 2010) finns det tydligt mönster för hur barn agerar och förväntas agera. Jällhage och Dilen (2013) rapporterar om att attityder hos ungdomar kan förändras vid ett aktivt genusarbete i skolan där elever tränas i att tänka normkritiskt. Om detta arbete introduceras redan i förskoleåldern finns möjlighet att attityder till normer kan förändras och att framtida samhällsmedborgare kan komma att ha större tolerans och acceptans för det normavvikande.

    En viktig aspekt för att få ett tolerant samhällsklimat är att barn möts med intresse och respekt. De bör uppmärksammas för sin person och känna sig trygga i de identiteter de skapar sig/finner. Det kan ibland krävas hjälp från vuxna till barnen med att tänka normkritiskt, detta arbete undersöker hur man kan gå till väga för att ge barn stöttning i sina funderingar kring livet.

    Detta projekt har lett till ett metodmaterial med tillhörande interaktiv aktivitetsmatta där barn får möjlighet att utforska, fundera och diskutera utifrån sin syn på världen. Aktivitetsmattan med handledning riktar sig till barn övre förskoleåldern och deras pedagoger.

  • 4036.
    Östberg, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Bungebråket: Analys av intresseavvägningar i tvisten om kalkbrytning på Bunge Ducker 1:642017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Konflikten kring kalkbrytning på Bunge Ducker 1:64 har pågått i över 10 år och är ännu inte avgjord när detta examensarbete skrivs. Det geografiska område som berörs går även under benämningen Ojnare eller Ojnareskogen. Två riksintressen står emot varandra; värnandet om naturen och de värden som finns i den brytbara kalken. För domstolarna Miljödomstolen respektive Miljööverdomstolen blev tvisterna en övning i intresseavvägning. I uppsatsen analyseras hur avvägningen genomfördes i två domar som kom till motsatta domslut. Miljödomstolen avslog i en dom från 2009 Nordkalks begäran om tillstånd för kalkbrytning, domen överklagades och Miljööverdomstolen gav i en dom 2010 tillåtlighet. I uppsatsen analyseras även en del av de intresseavvägningar som olika sakägare gjort med speciellt fokus på de sakägare vars intresse inte är givet i och med den verksamhet man bedriver eller sektorsansvar, framförallt länsstyrelsen i Gotlands län och region Gotland. För att fördjupa analysen av länsstyrelsens och regionens beslutsprocess har semistrukturerade intervjuer genomförts med tjänstemän på respektive myndighet. Regeringen fattade i 2015 beslut att under pågående rättsprocesser göra Ojnare till Natura 2000-område. Detta beslut kommer också att analyseras i uppsatsen. I analysen av intresseavvägningarna kommer aggregationsträd och nyttodifferenser att användas så långt det bidrar till förståelse av skeendet.

  • 4037.
    Östberg, Rasmus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Robustness of a neural network used for image classification: The effect of applying distortions on adversarial examples2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Powerful classifiers as neural networks have long been used to recognise images; these images might depict objects like animals, people or plain text. Distorted images affect the neural network's ability to recognise them, they might be distorted or changed due to distortions related to the camera.Camera related distortions, and how they affect the accuracy, have previously been explored. Recently, it has been proven that images can be intentionally made harder to recognise, an effect that last even after they have been photographed.Such images are known as adversarial examples.The purpose of this thesis is to evaluate how well a neural network can recognise adversarial examples which are also distorted. To evaluate the network, the adversarial examples are distorted in different ways and thereafter fed to the neural network.Different kinds of distortions (rotation, blur, contrast and skew) were used to distort the examples. For each type and strength of distortion the network's ability to classify was measured.Here, it is shown that all distortions influenced the neural network's ability to recognise images.It is concluded that the type and strength of a distortion are important factors when classifying distorted adversarial examples, but also that some distortions, rotation and skew, are able to keep their characteristic influence on the accuracy, even if they are influenced by other distortions.

  • 4038.
    Östblom, John
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Utredning av Valboåsens grundvattenmagasins förbindelse med Gavleån: En analys av halten löst syre genom mätningar2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Gävle municipality's water company is Gästrike Vatten AB. They manages the drinking water production for the City of Gävle. The production starts in the ridge of Valbo which extends between Överhärde (located in the south part of Valbo) and Strömsbro (located in the north part of Gavle). Purpose of this report is to measure the dissolved oxygen content in the aquifer throughout the whole area to investigate where the infiltration from the nearby Gavle River occurs. The aim of the study is to get a better understanding of the complexity of the Valbo ridge. The measurements will help to verify or modify the conceptual model of the directions of water flow in the Valbo ridge, developed by Midvatten AB. Dissolved oxygen content was measured through ground water pipes. To assess the pipes’ capacity and connection to the aquifer, slug tests were performed. The dissolved oxygen data were analyzed and compared with the conceptual model. The results showed that the dissolved oxygen content in the water supported the conceptual model to a large extent and also gave previously unknown information on some stretches of the ridge. The method shows great potential for additional future studies in Valbo ridge and elsewhere. To expand the study further, a need for more sampling of the aquifer throughout the areas that were not included in this study.

  • 4039.
    Östlin, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Tjockleksmätning med ultraljud: Icke konventionell metod med signalbehandling2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Ultrasonic thickness gauging of steel tubes is typically performed by observing the time difference between two following echoes. This process is often connected to various problems regarding interference. This thesis describes how to avoid these problems by using signal processing and analyzing the signals in the frequency domain.

    To achieve these results a signal model that describes the necessary effects is derived. From this model different measurement methods to analyze and determine the thickness are developed.

    One of the methods proved to be useful.

  • 4040.
    Östlund, Christine
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Dimensionering och optimering av ett solcellssystem för en industribyggnad i Mellansverige: En simuleringsstudie2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When converting to renewable energy systems, solar power as an energy source is a potential option; in order to achieve the climate and energy goal with 100% renewable energy production in year 2040. This is something the government try to achieve by making installation of solar cells more attractive through allowances such as subventions and tax reduction. The aim of this study was to analyze the effect of solar cell system on an industrial building in the midst of Sweden, in regard of economical-, technical- and climate related points of view. This was performed by replacing purchased electricity with locally produced electricity, where optimal circumstances for the solar power systems and the limits of the building has been taken into consideration during the dimensioning. With cost suggestions from a local authorized dealer the magnitude of the pay off time as a motivating factor was estimated. The local climate impact will be investigated through a litterature study, focusing on green house gas emissions. The dimensioning of the solar cell systems were based on empirical input from measurements in combination with documented data regarding the industrial building and simulated in the program Winsun PV. The study resulted in two different-sized systems with cost sheets that formed the basis for the calculated pay off time. System case 1 was dimensioned to keep the size of the nominal system effect to 255 kWp, this to avoid extra energy tax. The system gave an annual exchange of 228 MWh / year which gave the repayment period between 18 - 23 years. The system was simulated with an optimum angle of 39 ° in 15 ° azimuth direction of the modules. System case 2 was dimensioned to 1200 kWp in order to cover the effective usable surface of the roof, the system gave an annual exchange of 886 MWh / year and the repayment period was 22.5 - 25.1 years. The modules were simulated with the roof slope ± 4.7 ° in -15 ° azimuth direction. A further efficiency development for solar cell technology is required as well as an extended investment support from the County Administrative Board, to provide a more profitable exchange of solar cell systems in higher latitudes. If the solar cell system has a positive effect on the ecological footprint depends on where the solar cell is made and which electrical mix replaced by the produced solar energy.

  • 4041.
    Östlund, Christoffer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Framkomlighet i entréer på Högskolan i Gävle för personer med nedsatt rörelseförmåga2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    It is claimed that the modern society is built for everyone, yet many individuals with disabilities encounter problems in their everyday life that prevent them from feeling like a part of society. University of Gävle has been proven to have insufficiencies regarding availability. This has been exposed in surveys conducted by students in the Building Engineering Program.

    This thesis aims to identify the problems that exist at the ramps and entrances. To facilitate the investigation, the major entrances to the school were selected.

    The theoretical material consists of BBR 2014, Bygg ikapp 2014 and websites with related content. To find scientific articles websites such as Taylor & Francis Online, Academic Search Elite and Web of Science was used. These articles were discovered in the database in the library of The University of Gävle and the searches related to relevant literature that revolves around disabilities and accessibility in buildings.

    The study is based on two labs that has been named lab one and two. In lab one, the entrances were measured and this data was compared with previously established literature-data that describes what is acceptable when you are using a wheelchair. This data consists of measurements but also an inspection of existing resources. Lab two consisted of a practical test with a wheelchair and was based on an existing template used in checking accessibility. The purpose of the second test was to experience the problems firsthand and undergo these tests as a real-life experience.

    The results from both labs were very poor and many entrances showed major flaws at most checkpoints.

  • 4042.
    Östlund, Elin
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Träd, Miljö och Människor: Om konsten att välja träd efter platsens förutsättningar2010Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna uppsats ger en bild över hur man kan göra för att hitta det rätta trädet för platsen.

  • 4043.
    Östlund, Eric
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Lernholt, Kim
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Physical Activity Toolkit: Utveckling av en tillgänglig mobilapplikation för kognitivt funktionsnedsatta2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 4044.
    Östlund, Linda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Inställda förrättningar: Orsaker till inställande i Gävleborg, Dalarna och Jämtlands län 2013-20172018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sometimes obstacles arise in cadastral procedures that make it impossible to carry out the party's claim. An obstacle may be that property formation does not meet the conditions in chapter 3. or 5 chap. property formation (SFS 1970: 988). According to a press release issued by the Government Chancellor on January 19, 2017 (Regeringskansliet, 2017), the average processing time for an cadastral procedures is approximately 47.1 weeks at the Swedish mapping, cadastral and land registration authority (based on the last five years). The Swedish mapping, cadastral and land registration authority was commissioned to work towards shorten cases queues. By detecting obstacles in cadastral proceedings earlier, those cases that are not possible to be implemented can be removed from the case queue and help shorten the processing time.

    By examin cases that have been canceled due to a material barrier, a basis has been provided for reasons of resignation. During the period from 1 January to 31 december 2017, 74 cadastral procedurs were canceled in Gävleborg, Dalarna and Jämtland on due to material barriers.

    In view of the outcome of Klang (Klang, 2010) and the result of this work it can be concluded that the section of the law that most often cause barriers to cadastral procedurs are found in chapter 3 of the Property Formation Act.

    An examination of the property formation at an earlier stage would facilitate the work of the establishment. If obvious defects of appropriateness and conditions that are significantly contrary to the applicable land rules are discovered and can be resolved already at the first examination of the application, it could help reduce the processing time for that case. If not, the case would even be considered impracticable already there. However, in order to be able to make such an assessment at first examination, there is a certain kind of competence that is already lacking today.

  • 4045.
    Östlund, Robert
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Johansson, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Sentence First CAPTCHA: Proposal and study of a text based CAPTCHA scheme2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A major problem on the Internet is automated computer programs abusing services intendedto be used only by humans. Therefore, a method is needed to separate computersfrom humans. Completely Automated Public Turing Test To Tell Computers and HumansApart, or CAPTCHA, is a term used to describe a test that is difficult for computers andeasy for humans to pass and that can be generated and graded automatically. Most of theCAPTCHA schemes currently in use rely on some kind of image or audio recognitionproblem, making them unavailible to the visually and/or audially impaired. Additionally,visual CAPTCHAs can currently be broken with alarmingly high success rates. We proposea CAPTCHA scheme based purely in the text domain which we have named SentenceFirst CAPTCHA. The problem imposed on the users consists of classifying stochasticallygenerated sentences by fluency and legibility and pairs of sentences by semantic coherence.This scheme was implemented and tested by means of several surveys. The answers wereanalysed and the results show that this could very well be a feasible CAPTCHA scheme.

  • 4046.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Examples of training modules in Gävle, Berlin and Dublin2010Conference paper (Other academic)
  • 4047.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Introduction of the VESTA GIS project2010Conference paper (Other academic)
  • 4048.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Network for testing GI services2010In: Proceedings from Symposium GIS Ostrava 2010, 2010, p. 6 s.-Conference paper (Refereed)
  • 4049.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Verktyg för dataharmonisering baserade på öppen källkod2010In: Kartdagarna 2010 i Jönköping, 14-16 April, 2010Conference paper (Other academic)
  • 4050.
    Östman, Anders
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Bjerkman, Jan
    Future Position X.
    Regional GI Cluster in Support to the SDI Development2010In: International Conference SDI 2010 – Skopje, September 15-17 2010, 2010, p. 209-216Conference paper (Refereed)
7879808182 4001 - 4050 of 4051
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