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  • 101.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. Dept of Signal Processing, KTH Royal Institute of Technology, Stockholm, Sweden.
    Händel, Peter
    Dept of Signal Processing, KTH Royal Institute of Technology, Stockholm, Sweden.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Characterization and modeling of RF amplifiers with multiple input signals2016Conference paper (Refereed)
    Abstract [en]

    A characterization technique for RF PAs excited with multiple signals is presented. The technique can be used for characterization of memory effects in IM/CM products. The extracted information can in return be of use for modifying behavioral models to better capture memory in IM/CM products.

  • 102.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. Department of Signal Processing, School of Electrical Engineering, KTH.
    Händel, Peter
    Department of Signal Processing, School of Electrical Engineering, KTH.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Digital Predistortion of Single and Concurrent Dual Band Radio Frequency GaN Amplifiers with Strong Nonlinear Memory Effects2017In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 65, no 7, p. 2453-2464, article id 7855827Article in journal (Refereed)
    Abstract [en]

    Electrical anomalies due to trapping effects in Gallium Nitride (GaN) power amplifiers (PAs)give rise to long-term or strong memory effects. We propose novel models based on infinite impulse response (IIR) fixed pole expansion techniques for the behavioural modeling and digital pre-distortion of single-input-single-output (SISO) and concurrent dual-bandGaN PAs. Experimental results show that the proposed models outperform the corresponding finite impulse response (FIR) models by up to 17 dB for the same number of model parameters. For the linearization of a SISO GaN PA the proposed models give adjacent channel power ratios (ACPRs) that are 7 to 17 dBlower than the FIR models. For the concurrent dual-band case, the proposed models give ACPRs that are 9to 14 dB lower than the FIR models.

  • 103.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. ACCESS Linnaeus Centre, Department of Signal Processing, KTH Royal Institute of Technology, Stockholm.
    Khan, Zain Ahmed
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. ACCESS Linnaeus Centre, Department of Signal Processing, KTH Royal Institute of Technology, Stockholm.
    Isaksson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Händel, Peter
    ACCESS Linnaeus Centre, Department of Signal Processing, KTH Royal Institute of Technology, Stockholm.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Concurrent dual-band power amplifier model modification using dual two-tone test2016In: 46th Europena Microwave Conference (EUMC) 2016, 2016, p. 186-189Conference paper (Refereed)
    Abstract [en]

    A dual two-tone technique for the characterization of memory effects in concurrent dual-band transmitters is revisited to modify a 2D-DPD model for the linearization of concurrent dual-band transmitters. By taking into account the individual nonlinear memory effects of the self- and cross-kernels, a new2D modified digital pre-distortion (2D-MDPD) model is proposed,which not only supersedes the linearization performance but also reduces the computational complexity compared to the 2DDPDmodel in terms of a number of floating point operations(FLOPs). Experimental results show an improvement of 1.7 dBin normalized mean square error (NMSE) and a 58% reduction in the number of FLOPs.

  • 104.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH.
    Landin, Per
    Chalmers University of Technology.
    Händel, Peter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. ACCESS Linnaeus Centre, Signal Processing Lab, KTH Royal Institute of Technology.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Behavioral Modeling and Linearization of Crosstalk and Memory Effects in RF MIMO Transmitters2014In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 62, no 4, p. 810-823Article in journal (Refereed)
    Abstract [en]

    This paper proposes three novel models for behavioral modeling and digital pre-distortion (DPD) of nonlinear 2$,times,$ 2 multiple-input multiple-output (MIMO) transmitters in the presence of crosstalk. The proposed models are extensions of the single-input single-output generalized memory polynomial model. Three types of crosstalk effects were studied and characterized as linear, nonlinear, and nonlinear & linear crosstalk. A comparative study was performed with previously published models for the linearization of crosstalk in a nonlinear 2 $,times,$2 MIMO transmitter. The experiments indicate that, depending on the type of crosstalk, the selection of the correct model in the transmitter is necessary for behavioral modeling and sufficient DPD performance. The effects of coherent and partially noncoherent signal generation on the performance of DPD were also studied. For crosstalk levels of ${-}{hbox{30}}$ dB, the difference in the normalized mean square error and adjacent channel power ratio was found to be 3–4 dB between coherent and partially noncoherent signal generation.

  • 105.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH, Signalbehandling.
    Landin, Per N.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Händel, Peter
    KTH, Signalbehandling.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    2D Extended envelope memory polynomial model for concurrent dual-band RF transmitters2017In: International journal of microwave and wireless technologies, ISSN 1759-0795, E-ISSN 1759-0787, Vol. 9, no 8, p. 1619-1627Article in journal (Refereed)
    Abstract [en]

    The paper presents a 2D extended envelope memory polynomial (2D-EEMP) model for concurrent dual-band radio frequency (RF) power amplifiers (PAs). The model is derived based on the physical knowledge of a dual-band RF PA. The derived model contains cross-modulation terms not included in previously published models; these terms are found to be of importance for both behavioral modeling and digital pre-distortion (DPD). The performance of the derived model is evaluated both as the behavioral model and DPD, and the performance is compared with state-of-the-art2D-DPD and dual-band generalized memory polynomial (DB-GMP) models. Experimental result shows that the proposed model resulted in normalized mean square error (NMSE) of -51.7/-51.6dB and adjacent channel error power ratio (ACEPR) of -63.1/-63.4 dB, for channel 1/2, whereas the 2D-DPD resulted in the largest model error and DB-GMP resulted in model parameters that are 3 times more than those resulted with the proposed model with the same performance. As pre-distorter, the proposed model resulted in adjacent channel power ratio (ACPR) of -55.8/ -54.6 dB for channel 1/2 and is 7-10 dB lower than those resulted with the 2D-DPD model and2-4 dB lower compared to the DB-GMP model.

  • 106.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Mehmood, Imran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    DETECTION OF MULTIPLE TARGETS USING ULTRA-WIDEBAND RADAR2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    In recent years, ultra-wideband (UWB) radars are gaining popularity in the radar field mainly inindustrial and commercial areas. The UWB radar has the potential of dramatically improving thecontrol and surveillance of industrial processes in confined areas.The report provides an introduction to radar systems and detail working principle of M-sequenceUWB radar and methodology of how detection of targets is carried out. First two chapters of thereport describes the working of radar systems and M-sequence radar whereas in the later part ofthe report, different detection algorithms are discussed which has been implemented in thepresent radar simulations. In conventional radar the main detection algorithm is matched filteringwhere the transmitted signal is correlated with the received signal. Whereas UWB signal is nonsinusoidalthat is vulnerable to change in its shape during entire radar operation. This is thereason, the traditional signal processing methods like matched filtering or correlation process arenot advisable for UWB signals. Therefore, a different detection scheme known as Inter-periodcorrelation process (IPCP) has been studied.IPCP technique had been implemented and a comparison was made with the conventional targetdetection algorithm. On the basis of comparison made in this project, it has been observed thatthe conventional target detection methods are not effective in case of M-sequence UWB radar.The simulation results shows that by implementing IPCP method, performance close to 8-bitADC can be achievable with 1-bit comparator, also with IPCP implementation system resolutioncan be enhance effectively.Main focus was to analyze how close the system can detect two targets, therefore in all themeasurements i.e. practical and simulated measurements, only two targets were used.

  • 107.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics. KTH, Signalbehandling.
    Van Moer, Wendy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Händel, Peter
    Department of Signal Processing, KTH Royal Institute of Technology, Stockholm, Sweden .
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Characterization of concurrent dual-band power amplifiers using a dual two-tone excitation signal2015In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 64, no 10, p. 2781-2791, article id 7104121Article in journal (Refereed)
    Abstract [en]

    A method to characterize the memory effects in a nonlinear concurrent dual-band transmitter is presented. It is an extension of the conventional two tone test for power amplifiers to concurrent dual band transmitters. The output signal of a concurrent dual-band transmitter is affected not only by intermodulation products but also by cross-modulation products. In one frequency band, the transmitter is excited by a two tone signal which frequency separation is swept. In the second band the transmitter is concurrently excited by an other two tone signal with slightly wider frequency separation. The frequency difference of the two signals is fixed during the frequency sweep. The two tone test is made at different power levels. The upper and lower third-order inter- and cross-modulation products are measured. The asymmetry between the upper and lower third-order inter- and cross-modulation products are measures of the transmitter's memory effects. The measurement results show that the memory effects are more dominant in the third-order intermodulation products than in the cross modulation products. An error analysis and system calibration was performed and measurement results for two different devices are presented.

  • 108.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Van Moer, Wendy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Händel, Peter
    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 Electronics, Mathematics and Natural Sciences, Electronics.
    Rebuttal to "On Dual-Band Amplifications Using Dual Two-Tones Clarifications and Discussions"2017In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 66, no 10, p. 2795-2797Article in journal (Refereed)
    Abstract [en]

    This rebuttal is to "€œOn dual-band amplifications using dual two-tone: Clarifications and discussion". In the following, we provide our reply.

  • 109.
    Amin, Shoaib
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Zenteno, Efrain
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Landin, Per
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Isaksson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Händel, Peter
    ACCESS Linnaeus Centre, Signal Processing Lab, KTH Royal Institute of Technology.
    Noise Impact on the Identification of DigitalPredistorter Parameters in the Indirect LearningArchitecture2012In: 2012 Swedish Communication Technologies Workshop (Swe-CTW), IEEE conference proceedings, 2012, p. 36-39Conference paper (Refereed)
    Abstract [en]

    The indirect learning architecture (ILA) is the mostused methodology for the identification of Digital Pre-distorter(DPD) functions for nonlinear systems, particularly for highpower amplifiers. The ILA principle works in black box modelingrelying on the inversion of input and output signals of thenonlinear system, such that the inverse is estimated. This paperpresents the impact of disturbances, such as noise in the DPDidentification. Experiments were performed with a state-of-artDoherty power amplifier intended for base station operationin current telecommunication wireless networks. As expected,a degradation in the performance of the DPD (measured innormalized mean square error (NMSE)) is found in our experiments.However, adjacent channel power ratio (ACPR) canbe a misleading figure of merit showing improvement in theperformance for wrongly estimated DPD functions.

  • 110.
    Aminzoui, Abla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering.
    Vikten av kommunikation med inköpsavdelning: En studie ur medarbetarperpektiv i en fastighetsbolag2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purchasing function has become a strategic position for most companies. Activity in an organization cannot be performed without the presence of the information, which means that communication is important for being able to perform a task or activity. Communication related to the purchasing process has been investigated at Gavlegårdarna, a real estate company located in Gävle. In this work, Gavlegårdarna wanted to examine whether there is an opportunity to improve communication and investigate factors that lead to a lack of communication. The purpose of this study was to get a general image and increase understanding of factors that affect communication. The study is based on a case study, where one interview took place in the purchasing department and a questionnaire sent out to people who work daily with purchasing function.

  • 111.
    Amiot, Victor
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Torung, Rikard
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Oliksidig krympning i betong2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Concrete is one of the most commonly used building materials in foundation construction. Concrete is highly resistant to external stresses and hence makes it a very useful material in many different situations. However, there are problems that can arise with the use of concrete. One of the more common is cracking. There are several reasons why this might occur, for example, external impact, creep and moist-related movements. The concrete slab is one of the elements that often encounter this problem. Since concrete slabs are frequently used as foundation, it is of great interest to find solutions for this matter. In order to do that, the causes are needed to be specified more clearly. This study investigated experimentally how a concrete slab reacts when differences in humidity exposing the top and bottom after curing period, and if this may contribute to sufficient deformation to cause cracking. Six specimens were made and observed where three where exposed to a moisture content of 100% on the bottom. The remaining three samples have been placed in dry conditions in order to make a comparison possible. A relative humidity of 25% was measured in the surrounding air. The experiment showed clear differences in deformation between the two situations. The samples exposed to differential humidity exhibited sufficient stresses to cause cracking seen from the moment that occurred in the concrete. This shows that different prevailing humidity on the top and bottom of a slab can create sufficient stress to cause cracking.

  • 112.
    Amiri, Shahnaz
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Energisystem.
    Economic and Environmental Benefits of CHP-based District Heating Systems in Sweden2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Future energy systems and thus the climate are affected by many factors, such as energy resources, energy demand, energy policy and the choice of energy technologies. Energy systems of the future are facing three main challenges; the steady growth of global energy demand, the energy resource depletion, as well as the increasing emissions of carbon dioxide (CO2) and other greenhouse gases and their impact on climate change. To meet the mentioned challenges with sustainability in mind, actions that increase energy efficiency and choosing an energy-efficient energy system which is cost efficient will be essential. Combined heat and power (CHP) plants and district heating and cooling could contribute greatly to increased system efficiency by using energy otherwise wasted.

    The aim of this study is to increase the understanding of how CHP-based district heating and cooling systems using different primary energy sources can contribute to more cost-efficient energy systems, which reduce global CO2 emissions, and to highlight the impact of some important parameters and measures on Swedish municipal district heating systems. An important assumption in this study is the estimation of CO2 emissions from electricity production, which is based on marginal electricity perspectives. In the short term, the marginal electricity is assumed to come from coal-fired condensing power plants while in the long term it consists of electricity produced by natural gas-fired combined cycle condensing power plants. This means that the local electricity production will replace the marginal electricity production. The underlying assumption is an ideal fully deregulated European electricity market where trade barriers are removed and there are no restrictions on transfer capacity.

    The results show that electricity generation in CHP plants, particularly in higher efficiency combined steam and gas turbine heat and power plants using natural gas, can reduce the global environmental impact of energy usage to a great extent. The results confirm, through the scenarios presented in this study, that waste as a fuel in CHP-based district heating systems is fully utilised since it has the lowest operational costs. The results also show how implementation of a biogas-based CHP plant in a biogas system contributes to an efficient system, as well as lowering both CO2 emissions and system costs. The results show that replacing electricity-driven (e.g. compression) cooling by heat-driven cooling using district heating (e.g. absorption chillers) in a CHP system is a cost-effective and climate friendly technology as electricity consumption is reduced while at the same time the electricity generation will be increased. The results of the study also show that there is potential to expand district heating systems to areas with lower heat density, with both environmental and economic benefits for the district heating companies.

    The results reveal that the operation of a studied CHP-based district heating system with an imposed emission limit is very sensitive to the way CO2 emissions are accounted, i.e., local CO2 emissions or emissions from marginal electricity production. The results show how the electricity production increases in the marginal case compared with the local one in order to reduce global CO2 emissions. The results also revealed that not only electricity and fuel prices but also policy instruments are important factors in promoting CHP-based district heating and cooling systems. The use of electricity certificates has a large influence for the introduction of biogas-based cogeneration. Another conclusion from the modelling is that present Swedish policy instruments are strong incentives for cogeneration with similar impact as applying external costs.

  • 113.
    Amiri, Shahnaz
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Henning, Dag
    Optensys Energianalys, Linköping, Sweden .
    Karlsson, Björn G.
    Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden .
    Simulation and introduction of a CHP plant in a Swedish biogas system2013In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 49, p. 242-249Article in journal (Refereed)
    Abstract [en]

    The objectives of this study are to present a model for biogas production systems to help achieve a more cost-effective system, and to analyse the conditions for connecting combined heat and power (CHP) plants to the biogas system. The European electricity market is assumed to be fully deregulated. The relation between connection of CHP. increased electricity and heat production, electricity prices, and electricity certificate trading is investigated. A cost-minimising linear programming model (MODEST) is used. MODEST has been applied to many energy systems, but this is the first time the model has been used for biogas production. The new model, which is the main result of this work, can be used for operational optimisation and evaluating economic consequences of future changes in the biogas system. The results from the case study and sensitivity analysis show that the model is reliable and can be used for strategic planning. The results show that implementation of a biogas-based CHP plant result in an electricity power production of approximately 39 GW h annually. Reduced system costs provide a profitability of 46 MSEK/year if electricity and heat prices increase by 100% and electricity certificate prices increase by 50%. CO2 emission reductions up to 32,000 ton/year can be achieved if generated electricity displaces coal-fired condensing power.

  • 114.
    Amiri, Shahnaz
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Possibilities and consequences of deregulation of the European electricity market for connection of heat sparse areas to district heating systems2010In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, no 7, p. 2401-2410Article in journal (Refereed)
    Abstract [en]

    The objective of the study is to analyse the conditions for connection of residential buildings in heat sparse areas to district heating systems in order to increase electricity production in municipal combined heat and power plants. The European electricity market has been assumed to be fully deregulated. The relation between connection of heat sparse areas, increased electricity and heat production as well as electricity prices, fuel prices and emissions rights is investigated. The results of the study show that there is potential to expand the district heating market to areas with lower heat concentrations in the cities of Gavle, Sandviken and Borlange in Sweden, with both economic and environmental benefits. The expansion provides a substantial heat demand of approximately 181 GWh/year, which results in an electricity power production of approximately 43 GWh/year. Since the detached and stand-alone houses in the studied heat sparse areas have been heated either by oil boiler or by direct electricity, connection to district heating also provides a substantial reduction in emissions of CO(2). The largest reductions in CO(2) emissions are found to be 211 ktonnes/year assuming coal-fired condensing power as marginal electricity production. Connection of heat sparse areas to district heating decrease the system costs and provide a profitability by approximately 22 million EURO/year for the studied municipalities if the price of electricity is at a European level, i.e. 110 EURO/MWh. Sensitivity analysis shows, among other things, that a strong relation exists between the price of electricity and the profitability of connecting heat sparse areas to district heating systems.

  • 115.
    Amiri, Shahnaz
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Weinberger, Gottfried
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Increased cogeneration of renewable electricity through energy cooperation in a Swedish district heating system - A case study2018In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 116, p. 866-877Article in journal (Refereed)
    Abstract [en]

    The present study of the district heating (DH) system in the city of Kisa, Sweden, shows how, through energy cooperation with a nearby sawmill and paper mill, a local energy company contributes to energy-efficient DH and cost-effective utilization of a new biofuel combined heat and power (CHP) plant. Cases of stand-alone and integrated energy systems are optimized with the linear program MODEST. The European power market is assumed to be fully deregulated. The results show clear advantages for the energy company to cooperate with these industries to produce heat for DH and process steam for industry. The cooperating industries gain advantages from heat and/or biofuel by-product supply as well. The opening to use a biofuel CHP plant for combined heat supply results in cogenerated electricity of almost 29 GWh/a with an increased biofuel use of 13 GWh/a, zero fuel oil use and CO2 emission reductions of 25,800 tons CO2/a with coal-condensing power plant on the margin and biofuel as limited resource. The total system cost decreases by −2.18 MEUR/a through extended cooperation and renewable electricity sales. The sensitivity analysis shows that the profitability of investing in a biofuel CHP plant increases with higher electricity and electricity certificate prices.

  • 116.
    Amunarriz Ollokiegi, Endika
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Electric heated windows: thermal comfort and energy use aspects2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 117.
    Amundsen, Nicklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    The Possibilities and Limitations of Teaching Through Multi User Virtual Environments2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The use of computers has grown immensely in the last decades and the possibility to teach through them has grown as well. Various computer applications, games and forums have been created as tools of teaching and learning. This research project contains a summary of various works created within the E-learning area and their results. The virtual world Second Life is tested and some of the research in the literature review will be visited and examined. The research focuses on the feasibility to create scenarios for nursing students to practice patient care and handling, in addition to collaborative qualities that online virtual worlds offer. The conclusion taken from this research is that the possibilities far outweigh the limitations and that learning through virtual worlds should be further explored and developed.

  • 118.
    Anastasopoulou, Kyriaki
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Creation of a Low Energy Building with the help of Energy Simulation2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this Thesis Project, the creation of a Low Energy building was examined in order to investigate how complex was to select the suitable parameters and systems of the dwelling, aiming to achieve the lowest possible energy consumption in one year period. All the technologies implemented into the system intended to be as energy efficient and profitable as possible. Another objective of this study was also to present the potential of the system to produce a part of the consumed energy, through renewable energy sources, approaching by this way also the standards of a Zero Energy Building. Firstly, the floor plan of the 150 m2 detached house, was drawn in the designing program AutoCAD. In continuation, this 2D floor plan was imported into the simulation program as well as all the initial input data so as for the Base model of the building to be created For the analysis of the building, the Simulation Program IDA ICE 4.7 was used. Gradually, alternations and adjustments were made into the Base model. Different models were created planning to analyze their results and conclude to the proper solution. All the simulations run for one year time period in order to present the total energy usage, system’s losses and demands in each case. In addition, as for the current study, the location of the construction was Athens, all building’s characteristics were chosen to comply with the Greek Regulation for Low Energy Buildings. Finally, through the procedure followed after having accomplished a series of simulations, the final annually energy demands managed to be within the required limits.

  • 119.
    Andersen, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Wind Turbine End of Life: Characterisation of Waste Material2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Wind power is growing fast all over the world, and in Sweden alone thousands of turbines has been installed the last few decades. Although the number of decommissioned turbines so far is very low, the rapid installation rate indicates that a similar rapid decommissioning rate is to be expected shortly. If the waste material from these turbines is not handled sustainably the whole concept of wind power as a clean energy alternative is challenged.

    This study aims to present an accurate estimate of the amounts of waste material that will be generated from wind turbines in Sweden during the coming decades, allowing the waste management industry to plan for this and by extension prevent unnecessary energy losses through imperfect waste treatment. It should also present helpful information on how problematic waste can be reduced or avoided.

    VindStat’s annual report, presenting installation date and other relevant data for most installed turbines in Sweden, has been used as the base for the calculations. Information on material composition in different types and sizes of wind turbines has been extracted from various life cycle assessments, and by using the available parameters in the data base each turbine has been assigned a specific amount of steel, iron, copper, aluminum, blade material and electronics. An average life time of 20 years has been assumed, based on prior research and comparison with empiric data, and the material of each turbine is therefore seen as generated waste 20 years after installation date.

    To calculate the amount of waste material from replacing faulty components, empiric data over replacement rates in further developed markets has been combined with a prognosis over future development of installed wind capacity in Sweden based on a method described by prior research. As no sufficient way to predict how the future second hand market for turbines and components has been found, three different possible scenarios have been investigated to see how this may affect waste amounts.

    The results show that annual waste will grow slowly at about 12 % increase per year until around 2026, and then the average increase is 41 % per year until 2034. By then, annual waste amounts are estimated to have reached 237 600 tonne steel and iron (16 % of currently recycled amounts), 2 300 tonne aluminium (4 %), 3 300 tonne copper (5 %), 343 tonne electronics (<1 %) and 28 100 tonne blade material. There is no industrial scale recycling method for commonly used blade materials, and a high strength steel developed by Sandvik is proposed as a fully recyclable material to consider for further research. A well-functioning second hand market is shown to possibly have a major impact on waste amounts, at least in postponing it until better recycling systems are in place.

  • 120.
    Andersen, Niklas
    et al.
    Energi Funktion Komfort Skandinavien AB, Nacka, Sweden.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Hillman, Karl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Wallhagen, Marita
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Wind turbines’ end-of-life: Quantification and characterisation of future waste materials on a national level2016In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 9, no 12, article id 999Article in journal (Refereed)
    Abstract [en]

    Globally, wind power is growing fast and in Sweden alone more than 3000 turbines have been installed since the mid-1990s. Although the number of decommissioned turbines so far is few, the high installation rate suggests that a similarly high decommissioning rate can be expected at some point in the future. If the waste material from these turbines is not handled sustainably the whole concept of wind power as a clean energy alternative is challenged. This study presents a generally applicable method and quantification based on statistics of the waste amounts from wind turbines in Sweden. The expected annual mean growth is 12% until 2026, followed by a mean increase of 41% until 2034. By then, annual waste amounts are estimated to 240,000 tonnes steel and iron (16% of currently recycled materials), 2300 tonnes aluminium (4%), 3300 tonnes copper (5%), 340 tonnes electronics (<1%) and 28,000 tonnes blade materials (barely recycled today). Three studied scenarios suggest that a well-functioning market for re-use may postpone the effects of these waste amounts until improved recycling systems are in place.

  • 121.
    Andersmats, Edvin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Tapper, Dennis
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Team Foundation Server 2010: En utvärdering av mätetal för projektkvalitet2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    På Trafikverkets centrala funktion IT används Team Foundation Server 2010 för projekthantering. Utifrån detta system det är det möjligt att få fram mätetal som visar information om olika projekt. I denna fallstudie undersöks, med hjälp av intervjuer, vilka av dessa mätetal som kan användas för att visa en relevant bild av kvaliteten på ett systemutvecklingsprojekt. En modell presenteras för hur olika mätetal skulle kunna vägas samman för att fungera som en siffra på ett projekts kvalitet/hälsa. Till sist utvärderas om mätetal från TFS är tillräckliga för att ge en bra bild av kvaliteten på ett systemutvecklings-projekt. Studien kommer fram till att en sammanvägning är möjlig, men kan vara omfattande. Den visar även att mätetal från TFS är tillräckliga för att ge en övergripande bild av ett projekts hälsa.

  • 122.
    Andersson, Christine
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Linderdahl, Sofia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Ett förslag till arbetsmiljöplan för underhållsarbete inom bygg: en förenkling av rutiner för arbetsmiljöarbetet2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to the Swedish Work Environment Authority (Arbetsmiljöverket), accidents among construction workers occur twice as often as other workers. In 2015 the construction industry had over three thousand work accidents resulting in sick leave, which corresponded to eleven percent of Swedens total reported work accidents with sick leave. Considering what a worker in the building and construction industry expose themselves to in their daily work, it is obvious that focus must be towards safety.

    This study has been carried out on the building department for maintenance work at BillerudKorsnäs Gävle Bruk. At the company, there is a need for improving the establishment of safety and health plans within the existing working environment work. The aim and objective of the study is to create a draft template for the safety and health plan that is user friendly and includes the 13 works with special risks according to AFS 1999:3. Hopefully the template will contribute to a simplification of existing procedures in the construction working environment planning, lead to increased safety on site and fewer work accidents.

    To receive a better understanding of the viewpoint of BillerudKorsnäs Gävle Bruks construction workers regarding working environment and risks on site, semi-structured interviews were conducted and together with statistics on accidents and incidents, served as the studies results. In addition, a literature review has been conducted to provide an overview of previous studies in the field.

    The importance in carrying out risk assessments has been confirmed through interviews and becomes more evident as the conditions in the daily construction work varies in large proportion. Every work situation and risk is unique, therefore a risk assessment can not only consist of the 13 works with special risks. The interviews have confirmed the need for a simplification and improvement in the process of establishing a safety and health plan. A template for the safety and health plan should include how the work environment shall be conducted such as general information about the work and a risk assessment.

  • 123.
    Andersson, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Färdigställande av Sveriges digitala förrättningsarkiv: Effekter av skanning av äldre gällande förrättningsakter2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When the Swedish Mapping, Cadastral and Land Registration Authority, Lantmäteriet, first digitised their archived cadastral procedures into the digital archive Arken, the aim was to create a national digital archive for cadastral procedures. Lantmäteriet now have their cadastral procedures digitised in Arken. Some municipalities still have their older analogue cadastral procedures from 1972 and before archived in the office of their local authority. For the cadastral procedure, this means the land surveyor is bound to contact the local authority to reach all information needed for the procedure.

    A digitisation of the remaining older cadastral procedures may improve their availability and make todays cadastral procedure more effective and manageable for Lantmäteriet. This also applies to other users of these older archived documents. This dissertation aims to answer the following questions: 1) How may cadastral procedures become more effective and 2) become more legally certain through a digitisation of the analogue archives? 3) Which impact may a digitisation of these older archives have on the real property market and the Swedish municipalities? The research questions were answered through inventory of cadastral procedures and personal interviews with local authorities and other actors, experienced of or influenced by these matters. The inventory helped answering the amount of work remaining in digitising these archives. The interviews answered which impact a digitisation of the material would have on different users of the information. Interviews were also used together to investigate both the legal certainty of cadastral procedures and the quality of the Swedish land registry.

    The result of the dissertation shows which impact a digitisation would have on different users of the information. The most common effect of digitisation was effectiveness in different aspects, such as timesaving and cost-effectiveness along with legal certainty. Conclusions from the dissertation are: all interviewed users of the older cadastral procedures are positive to a digitisation of the material. More effort in time and finance from the different Swedish local authorities and Lantmäteriet is needed and strongly recommended.

  • 124.
    Andersson, Daniel
    et al.
    Radarbolaget.
    Björsell, Niclas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Ottoson, Patrik
    Radarbolaget.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Radar Images of Leaks in Building Elements2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 78, p. 1726-1731Article in journal (Refereed)
    Abstract [en]

    Through leakage in the building envelope there is a penetration of air, water vapor and particles. The degree of leakage of air can be quantified by existing methods. However, the location of adventitious openings is often not known. In order to overcome the limitations in existing methods, a non-contact and non-destructive method based on ultra-wide bandwidth radar technology is suggested. A test-bed is designed that can measure with different polarization to be able to detect flaws in different directions. Initial measurements shows promising results for further development of the method of using radar images to find leaks in building elements.

  • 125.
    Andersson, Daniel
    et al.
    Radarbolaget, Gävle.
    Wallin, Kjell
    Radarbolaget, Gävle.
    Javashvili, Otar
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Beckman, Claes
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    M-Sequence UWB Radar for Industrial Applications2010In: Program of GigaHertz Symposium 2010, March 9-10, at Lund University, 2010Conference paper (Other academic)
    Abstract [en]

    Ultra Wideband Radar has the potential of dramatically improving the control and surveillance of industrial processes in confined areas. An example is the application of UWB radar for surveillance of furnaces for heath treatment of steel billets developed by Radarbolaget in Gävle.

    In our installation at AB Sandvik Materials Technology, we have shown that by using a non-destructive UWB Radar technique it is possible to visualize in real-time the ongoing process inside the furnace behind a 0.5 m thick ceramic wall. Since the operating temperature inside the furnace is 1200 °C, there is today no other known method capable of visualizing the process for the operator of the furnace. The system is therefore designed to sustain high temperatures and powerful electromagnetic disturbances while performing measurement with wide dynamics and high stability.

    The design of this radar is based on the idea of transmitting a continuous m-sequence and then detecting the correlated impulse response (see figure below). The wide bandwidth is a requirement for obtaining high spatial accuracy and resolution but puts further requirements on the design of the antennas and the electronics. Our results show that with this technique it is possible to determine the deformation of the steel billets inside the furnace with an accuracy of less than 5 mm. The radar system is also able to detect deformations in the furnace wall

    The m-sequence radar has many advantages over other UWB radar technologies since it e.g. does not require many analogue components. Its performance is a result of the choice of code length, sampling rate and averaging. However, the resolution is still limited by the impulse response of the analogue antenna (ringing).

    In this paper system parameters that affect the overall performance of an m-sequence radar are reviewed and means of enhancing its performance are discussed.

  • 126.
    Andersson, David
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Olsson, Philip
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Hur kan en skola med högre energianvändning än det svenska genomsnittet energieffektiviseras?: Energikartläggning2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The European Union as a whole is one of the largest energy users and has one of the world's largest greenhouse gas emissions. To reduce global warming, targets have been set to ensure that the average temperature on the earth does not increase more than 2 degrees since the pre-industrial time. Nearly 40% of Sweden's total energy use comes from the building and services sector which in context with that the 2020 targets approaching contributes to the increased need of higher energy efficiency of buildings. Energy audits is a tool for determining what has the greatest potential for saving energy before efficiency measures occurs.

    The thesis includes an energy audit of Trödje primary and middle school, administered by Gavlefastigheter. The study was performed using IDA Indoor Climate and Energy simulation tool. IDA ICE was used to modulate the existing building where all data for the school was included. The vision of the thesis is to investigate how much energy which is possible to save through energy saving measures and which action that is most effective.

    The potential energy saving in the school is high, the school uses 42.6 kWh/m2year more than the average for Gavlefastigheter schools, which corresponds to 21 %. The results show that the complexity of the school and the reconstruction, also called the paviljong, are a major factor in the high energy consumption. The school's energy use has a potential to decrease by 17 %, which did not correspond to the 25 % target set for the work. The work shows that the greatest savings potential exists through the exchange of windows and heat exchangers in the ventilation system, but also that the measures that are assumed to give the greatest savings are not always the most effective.

  • 127.
    Andersson, Elisabeth
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Maria, Reineck
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Betydande faktorer för effektiva specialtransporter2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To be competitive in the market, companies need to find and use available resources for improvements. Transport is a source to cost-effective and customer accessible logistics system. Both internal and externals transports are important to focus on when processes are optimized in order to obtain lower costs. The main logistics cost in many companies constitutes of transports.

     

    This case study has been conducted in an industrial company. This study intends to make the transports more effective, through better customer service and reduced costs. The transports that have been studied are not directly linked to the production. When a transport is needed an order is made by telephone.

     

    The purpose of the study is to identify significant factors for effective special transports. The factors form a foundation for recommendations to the case company in the future work to have more effective special transports. To answer the purpose literature studies, observations, data analysis, interviews and benchmarking have been carried out. Some significant factors for effective special transports are information, effective logistics and standardization. Some identified waste in the case company is lack of communication and information and the utilization of resources. The significant factors have a correspondence with the identified waste.

  • 128.
    Andersson, Emelie
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Hållbar utveckling i läroböcker för naturkunskap 1b2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Miljöundervisning har funnits länge och idag är det fokus på hållbar utveckling som har sitt ursprung från 1970- och 1980-talet. Det är ett begrepp har kritiserats av många för sin komplexitet. Hållbar utveckling har fått mer utrymme i den nyutformade kursplanen för kursen naturkunskap 1b i och med den nya läroplanen Gy11. Hur väl anpassade är då de nya läroböckerna för syfte och centralt innehåll för kursen naturkunskap 1b inom området hållbar utveckling? För att utföra undersökningen har de fem aktuella läroböckerna för kursen naturkunskap 1b lästs i fem omgångar, en analys av textens innehåll, frågor och illustrationer har utförts. Undersökningen visar på att det varierar hur väl de fem olika läroböckerna behandlar hållbar utveckling, samtliga fem läroböcker behandlar dock ämnet. Störst brister finns framförallt inom jämställdhet och mänskliga rättigheter. Det är generellt mer fokus på att presentera (och lära ut) fakta än att eleverna skall göra ställningstaganden, illustrationerna i läroböckerna är relevanta till texten. 

  • 129.
    Andersson, Emelie
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Undersökningav oosporförekomst från kransalger i sediment från olika provtagningspunkter i en gloflad i Gårdskärsområdet2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Längs den svenska kusten verkar landhöjningen, en process där landet höjs efter den senaste istiden. Mest påtaglig är landhöjningen i Östersjön. Till följd av landhöjningen avsnörs grunda havsvikar från havet och bildar nya sjöar, så kallade flader, gloflader och glon. Målet med denna studie var att undersöka sediment från olika provtagningspunkter i en gloflad i Gårdskärsområdet i Lövstabukten (norra Uppland), för att se hur fördelningen av olika arter av kransalger varierat i glofladen under åren när miljön successivt förändrats. För att undersöka detta har oosporförekomst från kransalger i sediment studerats. I det undersökta området får landhöjningen verka ganska ostört, vilket gör det intressant att undersöka just detta område. Denna undersökning visar att Chara aspera, Chara globularis och Chara tomentosa tidigare funnits i den undersökta glofladen. C. aspera förekom vid samtliga fem provtagningspunkter och under längst tid, medan C. globularis noterades vid två provtagningspunkter och C. tomentosa fanns vid endast en provtagningspunkt och är den art som växt i glofladen under de senaste åren. Inga stora skillnader fanns i sedimentet mellan de fem olika provtagningspunkterna. Färgen varierade från mossigt grön och vattenrik i ytsediment till fast lera i de djupare delarna av sedimentet.  

  • 130.
    Andersson, Emelie
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Aziz, Shniar
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    En jämförelse mellan gröna-, metall- och gråa tak för ett oisolerat parkeringshus utifrån dess olika temperaturer och dagvattenhantering2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Since climate change increases and changes constantly, it contributes to higher average temperatures, ice melting and has a great impact on our ecosystem. This will then lead to a warmer climate, which means increased precipitation and milder winters. One of the reasons to climate change is urbanization, meaning people moving to the cities. To succeed in changing the climate, international cooperation and common goals are required. At the northern part of Brynäs, in the municipality of Gävle, work is currently in progress around the area where the factory of Läkerol was once standing. The area continues to be rebuilt and the outcome will eventually be called Godisfabriken. There, amongst other, a car park will be built for the newly built homes. The aim of this study is to compare metal roofs, grey concrete roofs and green roofs within the two aspects of stormwater management and temperature. Then analyse which alternative of these three roofs would be most advantageous for the car park of Godisfabriken.

     

    The focused roofs are green, metal and concrete. A green roof is when it's completely or partly covered by a layer of vegetation and metal roofs are different sheet roofs with steel and aluminium-zinc. Grey roofs are made of concrete which works as both floor and ceiling. A building's roof affects which air temperature the surroundings has with its slope, vegetation and surrounding buildings. Another problem with urbanization and a warmer climate is stormwater management, which means rain and melted snow from roofs, parking areas and other hard surfaces.

     

    The method includes a literature study and calculations. The literature study gave research on temperature for all roofs as well as stormwater management for green roofs. Calculations were made for stormwater management and temperature with its flow, absorption, reflectance and heat transfer.

     

    The literature study and the calculations showed that green roofs have a high SRI value of 80 while the remaining roof is at around 40. The higher SRI, the lower surface temperatures on the material. This is proven in both methods when green roofs according to the literature study received a maximum surface temperature of 38 °C and 48 °C. According to the literature study green roofs can preserve more than 50 % of the rainwater. They also had a water flow rate of 1.97 l/s, which is less than half of what the metal roof got in the calculations. Since green roofs had both low air and surface temperatures, as well as longer drainage times and most absorbed water, green roofs are a more suitable choice than metal and grey concrete.

  • 131.
    Andersson, Erik
    et al.
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden .
    Barthel, Stephan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering. Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Memory carriers and stewardship of metropolitan landscapes2016In: Ecological Indicators, ISSN 1470-160X, E-ISSN 1872-7034, Vol. 70, p. 606-614Article in journal (Refereed)
    Abstract [en]

    History matters, and can be an active and dynamic component in the present. We explore social-ecological memory as way to diagnose and engage with urban green space performance and resilience. Rapidly changing cities pose a threat and a challenge to the continuity that has helped to support biodiversity and ecological functions by upholding similar or only slowly changing adaptive cycles over time. Continuity is perpetuated through memory carriers, slowly changing variables and features that retain or make available information on how different situations have been dealt with before. Ecological memory carriers comprise memory banks, spatial connections and mobile link species. These can be supported by social memory carriers, represented by collectively created social features like habits, oral tradition, rules-in-use and artifacts, as well as media and external sources. Loss or lack of memory can be diagnoses by the absence or disconnect between memory carriers, as will be illustrated by several typical situations. Drawing on a set of example situations, we present an outline for a look-up table approach that connects ecological memory carriers to the social memory carriers that support them and use these connections to set diagnoses and indicate potential remedies. The inclusion of memory carriers in planning and management considerations may facilitate preservation of feedbacks and disturbance regimes as well as species and habitats, and the cultural values and meanings that go with them.

  • 132.
    Andersson, Fredrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Applikationsutveckling för Android2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta projekt handlar om ett applikationsutvecklingsprojekt för Androidplattformen vilket innefattar Androids uppbyggnad, Javaprogrammering, design i XML miljö, grunder i Eclipse samt publicering på Google Play (före detta Android market). Projektet resulterar i en Androidapplikation i form av ett enkelt Pongspel med olika funktioner som highscorelista samt att uppsatsen beskriver det man behöver kunna för att utveckla applikationer för Android.

  • 133.
    Andersson, Fredrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Utveckling av GIS-applikation för effektivisering av planeringsarbeten för infrastruktur2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Planeringsarbeten för infrastruktur sker ofta med hjälp av speciella programvaror som CAD för att skapa ritningar på kartor över områden där tänkta infrastrukturer skall utvecklas. Som en effektivisering för dessa arbeten handlar denna studie om implementering av en GIS-applikation för att motivera fördelar med GIS och sättet för hantering samt visualisering av geografisk information. En webbapplikation som hanterar baskartor samt överliggande vektorlager för infrastruktur utvecklas, samt även att samma kartdata över infrastrukturen kopplas till en mobilapplikation för att effektivisera eventuella inventeringsarbeten av infrastrukur med hjälp av GPS för att kunna positionera infrastruktur på ett bra sätt. Tekniken bakom utvecklingen bygger på HTML, CSS och JavaScript samt molntjänstlagrin av infrastruktursdata i en geodatabas . GIS-applikationen sammanställer svar på frågor som bevisar hur GIS på ett tillfredställande sätt mycket väl skulle kunna implementeras och användas praktiskt i ett utvecklingsarbete för infrastruktur i dagens morderna samhälle. 

  • 134.
    Andersson, Harald
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Numerical and experimental study of confluent jets supply device with variable airflow2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In recent years, application of confluent jets for design of ventilation supply devices has been studied. Similarly, numerus studies have been made on the potential and application of variable air volume (VAV) in order to reduce the energy demand of ventilation systems. This study investigates the combination of supply devices based on confluent jets and VAV, both in terms of the nearfield flow behavior of the device and the impact on thermal comfort, indoor air quality and energy efficiency on a classroom-level space when the airflow rate is varied.

    The method used in this study is an experimental field study where the confluent jets-based supply devices were compared to the previously installed displacement ventilation. The field study evaluated the energy efficiency, thermal comfort and indoor air quality of the two systems. In the case of the confluent jets supply devices, airflow rate was varied in order to see what impact the variation had on the performance of the system for each airflow rate. Furthermore, the confluent jets supply devices were investigated both experimentally and numerically in a well insulated test room to get high resolution data on the particular flow characteristics for this type of supply device when the airflow rate is varied. The results from the field study show nearly uniform distribution of the local mean age of air in the occupied zone, even in the cases of relatively low airflow rates. The airflow rates have no significant effect on the degree of mixing. The thermal comfort in the classroom was increased when the airflow rate was adapted to the heat load compared to the displacement system. The results lead to the conclusion that the combination of supply devices based on confluent jets can reduce energy usage in the school while maintaining indoor air quality and increasing the thermal comfort in the occupied zone.

    The results from the experimental and numerical study show that the flow pattern and velocity in each nozzle is directly dependent on the total airflow rate. However, the flow pattern does not vary between the three different airflow rates. The numerical investigation shows that velocity profiles for each nozzle have the same pattern regardless of the airflow rate, but the magnitude of the velocity profile increases as the airflow increases. Thus, a supply device of this kind could be used for variable air volume and produce confluent jets for different airflow rates.

    The results from both studies show that the airflow rate does not affect the distribution of the airflow on both near-field and room level. The distribution of air is nearly uniform in the case of the near-field results and the room-level measurement shows a completely uniform degree of mixing and air quality in the occupied zone for each airflow rate. This means that there is potential for combining these two schemes for designing air distribution systems with high energy efficiency and high thermal comfort and indoor air quality.

  • 135.
    Andersson, Harald
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energy-Saving Measures in a Classroom Using Low Pressure Drop Ceiling Supply Device: A Field Study2016In: 2016 ASHRAE Winter Conference Papers, ASHRAE, 2016Conference paper (Refereed)
    Abstract [en]

    Between 1990 and 2006 the energy use by ventilation systems in Swedish schools doubled. This is explained by high airflows in schools because of the high occupant density. Studies show that 87% of Swedish schools use constant air volume (CAV), and it is estimated that a change to variable air volume (VAV) could save 0.12-0.33 TWh (4.1*10(12) - 1.1*10(13) Btu) per year. Therefore the aim of this study is to investigate whether it is possible to replace displacement ventilation (DV) with mixing ventilation (MV) to create a comfortable indoor climate in a typical classroom and at the same time decrease the energy use by using VAV and Low Pressure Drop Ceiling Supply Device (LPDCSD). The study used two LPDCSDs which consist of circular channels with 190/228 round jets placed in an interlocking pattern, with a horizontal one/two-way-direction. The field study was carried out in a school which is intended to be extensively renovated. The school currently has DV and CAV. The study was carried out by installing MV with LPDCSD in one of the typical classrooms. Several different air-flow rates were investigated using tracer-gas technology to measure the local mean age of the air in the occupied zone. Simultaneously, thermal comfort and vertical temperature gradients were measured in the room. The results show nearly uniform distribution of the local mean age of air in the occupied zone, even in the cases of relatively low air-flow rates. Since the mixing of air is more or less the same in the entire occupied zone VAV can be used to reduce air-flow rate based on the desired CO2-level. Because of the number of students in each classroom and the fact that changes in air-flow rates have no significant effect on the degree of mixing, it is possible to reduce the air-flow rates for extended periods of time. Finally, since the LPDCSD has a lower pressure-drop than the currently used supply devices and it is possible to use VAV to lower the airflows in cases with reduced heat loads, it is possible to significantly reduce the energy usage in the school while maintaining the IAQ, increasing the thermal comfort and the available floor area of the occupied zone.

  • 136.
    Andersson, Harald
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Experimental and numerical investigations of a new ventilation supply device based on confluent jets2018In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 137, p. 18-33Article in journal (Refereed)
    Abstract [en]

    In developed countries, heating, ventilation, air conditioning (HVAC) systems account for more than 10% of national energy use. The primary function of a HVAC system is to create proper indoor environment. A number of ventilation strategies have been developed to minimize HVAC systems’ energy use whilst still maintaining a good indoor environment. Among these strategies are confluent jet ventilation and variable air volume. In this study, an air supply device with a novel nozzle design that uses both of the above-mentioned strategies was investigated both experimentally and numerically at three different airflow rates. The results from the numerical investigation using the SST k - ω turbulence model regarding velocities and flow patterns are validated by experimental data carried out by Laser Doppler Anemometry. The results from both studies show that the flow pattern and velocity in each nozzle is directly dependent on the total airflow rate. However, the flow pattern does not vary between the three different airflow rates. The numerical investigation shows that velocity profiles for each nozzle have the same pattern regardless of the airflow rate, but the magnitude of the velocity profile increases as the airflow increases. Thus, a supply device of this kind could be used for variable air volume and produce confluent jets for the airflow rates investigated.

  • 137.
    Andersson, Helena
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Åhsberg, Mela
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Debiteringsmodell för interna transporter: Hur en debiteringsmodell kan förändra beställningsbeteende och sänka kostnader2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Transfer pricing is the price of goods or services supplied between units within a larger company. It turns out that transfer prices can make it possible for a company to be more effective and direct the company towards the common targets. A payment model can be used to connect internal charging for a completed delivery, where a written request is sent electronically to the customer with information about the amount and in which account the money should be placed. The specified price is based either on the basis of a price list that is updated continuously, or calculated immediately after a completed delivery. By using the service levels in a payment model the ordering behavior in the internal logistics can be changed if a manager makes the workers aware of how their choices affect the production unit's finances.

     

    The purpose of this study is to investigate whether a payment model for internal transport can change ordering behaviors and reduce costs for internal logistics. The purpose has been filled by performing a literature review on the subject which has been conducted on a case company where the internal ordering behavior and the current payment model have been studied. After examining and documenting of the current situation on the case company, a new payment model has been developed. The new payment model consists of hard and soft factors, where the factors are strongly linked with each other and are important to change unwanted behaviors.

     

    The result of the survey shows that a payment model alone cannot change unwanted ordering behavior. Unwanted ordering behavior can only be changed with the combination of service levels and strong leadership.  The target is to make workers aware that the choice of service level affects the final price of an order. It can only happen if managers motivate the workers to choose a service level that can reduce production unit ordering costs. It is however important to note that the payment model itself must be supported by a strong leadership that promotes a change and that workers receive training in how the payment model works and knowledge of what management's view of the model is.

     

    With this background, this study aims to solve both the case company’s practical problems with internal transport costs and increasing knowledge about payment models and how these can be used to change unwanted behaviors.

  • 138.
    Andersson, Jacob
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Norbäck, Markus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Lokalisering av nya bostadsområden i översiktlig planering: En rumslig multikriterieanalys över Gävle2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Urbanization combined with toxic emissions from motor traffic calls forhigher demands when house planning in cities. The purpose of this study is toincrease understanding about how to apply multi criteria analyses whenmaster planning to contribute to a more sustainable society. A more effectivehouse planning connected to existing societal functions might add to the usageof more sustainable transportation alternatives rather than that of cars.

    Using the input from interviews with representatives from both the privateand the public sector, a number of criterias have been developed for theanalysis. Considering existing societal functions, this study was intended toidentify new areas for housing development using a multi criterial analysis.This might contribute to more sustainable transportation because of thedistance to the societal functions. In addition to this, the intention extended tothe investigation of how political interests differs from one another, using aranking system based on the developed criterias.

    The results show that representatives from the two largest political parties in asmall town in Sweden rank the criterias different when it comes to whatsocietal functions a new housing area should have in close proximity. On theother hand, the end results show that the areas chosen for housingdevelopment have similar qualities, in spite of varying housing politics amongthe politicians. This study might contribute to a more effective politicalhandling of business, since political differences does not ultimately showdifferences in where activities or objects should be placed.

  • 139.
    Andersson, Johan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Hiller, Thomas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Mobile Learning för elever med läs- och skrivsvårigheter2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna utredning visar att förekomsten av mobilapplikationer specifikt riktade till dyslektiker är i det närmaste obefintlig. Dessutom är forskningen på området M-Learning mest inriktad på integrerade M-Learning-system och inte på enskilda applikationer. M-Learning (mobilt lärande) är ett forskningsområde som kan sägas vara en vidareutveckling av E-Learning. Detta är ett växande forskningsområde och med explosionen av smarta telefoner och surfplattor bör för- och nackdelarna med  M-Learning kunna utnyttjas i större utsträckning. På uppdrag av Gävle kommun och med handledning av Sogeti har en prototyp mobilapplikation för elever med dyslexi utvecklats för Android-plattformen. Prototypen som framtagits visar att en mobilapplikation för elever med dyslexi med fördel kan utnyttja mobila enheters multimodalitet.

  • 140.
    Andersson, Jonas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Hedlund, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Undersökning om handhållna laserskannrar vid detaljmätning: En jämförelse mellan multistationen Leica Nova MS50 och den handhållna laserskannern FARO Freestyle X2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Terrestrial laser scanners (TLS) have been common in geodetic measurements for over 10 years. The technology is developing rapidly and specialized instruments are launched constantly. One type of these specialized TLS instruments are hand-held laser scanners. They are designed primarily to generate point clouds of spaces and small objects where the traditional tripod mounted laser scanner has difficulties to scan. When the hand-held laser scanners are relatively new, the research on the instruments is limited, and the lack of standardized control methods. With that in mind it is important to study the instruments. In this thesis the hand-held laser scanner FARO Freestyle X was investigated on how well the handheld laser scanning technology really is and what limitations the instruments have. This was done by comparing point clouds from FARO Freestyle X with reference point cloud generated by Leica's multi-station MS50. To study the instrument a number of parameters was investigated such as scanning distance, ease of use, time and performance. These parameters were considered to be sufficient basis for conclusions about the instrument's advantages/disadvantages and limitations.

    The result of the point cloud comparison from the short distance showed deviations around 10 mm and then increase to few centimeters at longer distances. Volume limitation control showed no differences compared to the scanning from short distance. This means that moving the instrument does not affect the results significantly. The instrument's Achilles' heel is the noise that occurs when scanning from longer distances, about 30 mm deviations. Even the type of object affects the noise. The noise on the wall showed the greatest deviation while the noise on the table indicated the lowest results. The repeatability showed good results visually and had similar deviations. The instrument has a good ability to recreate objects when the resolution test demonstrates good performance. Main advantage of the instrument is its effective documentation of smaller objects, but also some larger areas where the uncertainty of centimeter-level is required. The ease of use can be described as good and the colored point clouds takes visualization to a new level. The results of the study show that the hand-held laser scanners can, potentially, challenge the traditional laser scanner.

  • 141.
    Andersson, Kristina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    "It's funny that we don't see the similarities when that's what we're aiming for": Visualizing and challenging teachers' stereotypes of gender and science2012In: Research in science education, ISSN 0157-244X, E-ISSN 1573-1898, Vol. 42, no 2, p. 281-302Article in journal (Refereed)
    Abstract [en]

    This study illuminates teachers’ conceptions of gender and science and possibilities to challenge these conceptions. Since 2005, a group of teachers (K-6) inSwedenhave met approximately once a month in two-hour seminars to discuss and develop their instruction in science and technology based on a gender perspective. The present data consist mainly of audio-recordings of the teacher seminars and video-recordings of science/technology activities with students. Analysis of the empirical data has been carried out in several stages and was inspired by thematic analysis, the theoretical framework of which is based on Hirdman’s and Beauvoir’s theories of gender. The results show that the teachers’ ideas about gender/equity and science exist on several levels, within which various conceptions are represented. On the one hand, “reasoning around similarity”, where teachers consider that both girls and boys should have the same prerequisites for working with science/technology. In contrast, stereotyped conceptions of girls and boys when the teachers evaluate their activities with students, where condescending attitudes toward girls are also observed. The girls’ ways of working with science/technology are not as highly valued as the boys’, and this outlook on children can ultimately have consequences for girls’ attitudes toward the subject. When teachers are allowed to read their own statements about the girls, they get “a glimpse of themselves”, and their condescending ideas about girls are made visible. In this way, the teachers can begin their active work toward change, which may lead to new outlooks on and attitudes toward students.

  • 142.
    Andersson, Kristina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Krönika: utbytta ord kan motverka fördomar2011In: Genus, ISSN 1403-8943, no 2, p. 25-25Article in journal (Other (popular science, discussion, etc.))
  • 143.
    Andersson, Kristina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Lärare för förändring: att synliggöra och utmana föreställningar om naturvetenskap och genus2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main focus in this thesis is teachers’ gender awareness related to scientific practice. The thesis is based on two different empirical studies: a longitudinal action research study together with a group of teachers (K-6) and a study during an in-service development course where experienced teachers applied gender theory on a real classroom situation, a case. 

     

    The studies show that working with gender is complicated and comprises of many aspects of human life. An important part of gender awareness is to be able to relate to these aspects. A question of vital importance is to challenge conceptions of gender in such a way that the conceptions will be verbalized and thereby visualized. Moreover, the studies show that feminist pedagogy and theory of science can lead to a new approach to teaching and learning in science. For teachers without any background in science, there are other competences than just subject matter knowledge that are vital for teaching. Feminist perspectives in professional development reinforce teachers’ pedagogical competences and their pedagogical content knowledge and thereby make these teachers feel they participate in the scientific practice and contribute in developing both the stuff of knowledge and its culture.

     

    The thesis also contributes to new methodological knowledge about action research. One of the results is that time is an important factor to take into consideration depending on what kind of change you want to receive. The researcher engaged in action research as an "outsider" has an important function in order to monitor the process and pay attention and use critical events to drive the change process forward.        

     

  • 144.
    Andersson, Kristina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Vad har genus med naturvetenskap att göra?2013In: Den onaturliga naturen: Kunskapsmaterial om sexualitet och kön för lärare i naturkunskap och biologi på gymnasiet / [ed] Hans Olsson, Tommy Eriksson, RFSU , 2013Chapter in book (Other academic)
  • 145.
    Andersson, Kristina
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Danielsson, Anna
    Faculty of Education, University of Cambridge.
    Gullberg, Annica
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Hussénius, Anita
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Chemistry.
    Acting for change: Challenging teachers through theatre, interventions and research2011Conference paper (Refereed)
  • 146.
    Andersson, Kristina
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Danielsson, Anna
    Institutionen för pedagogik, didaktik och utbildningsstudier, Uppsala universitet.
    Gullberg, Annica
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Hussénius, Anita
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Chemistry.
    Chasing borderlands - pre-service teachers' meeting with different cultures in their education2012Conference paper (Refereed)
  • 147.
    Andersson, Kristina
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology. Centre for Gender Research, Uppsala University.
    Gullberg, Annica
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology. Centre for Gender Research, Uppsala University.
    What is science in preschool and what do teachers have to know to empower children?2014In: Cultural Studies of Science Education, ISSN 1871-1502, E-ISSN 1871-1510, Vol. 9, no 2, p. 275-296Article in journal (Refereed)
    Abstract [en]

    In this article we problematize the purpose of teaching science in preschool and what competences preschool teachers need in order to conduct science activities in the classroom. The empirical data were collected through an action research project with five preschool and primary school teachers (K-6). In the first section we have used one situation, a floating-sinking experiment, as an illustration of how two different epistemological perspectives generate different foci on which kind of science teaching competences that are fruitful in preschool. In the first perspective, the central goal of science teaching is the development of the children’s conceptual understanding. With this perspective, we found that the science activities with the children were unsuccessful, because the children’s thoughts about concepts did not develop but even the situation enhanced a misconception concerning density. Moreover, the teacher was unsuccessful in supporting the children’s conceptual learning. The second perspective uses a feminist approach that scrutinizes science, where we investigate if the floating-sinking activity contributes to a feeling of participation in a scientific context for the children and if so how the teacher promotes this inclusion. This second perspective showed that the children’s scientific proficiency benefited from the situation; they had acquired a positive experience of the density concept that they could build upon which was reinforced by the teacher. The children discovered that they had power over their own learning by using an experimental approach. On the basis of these findings, we conclude that there are competences other than subject matter knowledge that are also important when preschool teachers engage children in scientific activities. Through process-oriented work with the teacher group, we identified four concrete skills: paying attention to and using children’s previous experiences; capturing unexpected things that happen at the moment they occur; asking questions that challenge the children and that stimulate further investigation; situated presence, that is, “remaining” in the situation and listening to the children and their explanations. We discuss possible ways to move preschool teachers away from their feelings of inadequacy and poor self-confidence in teaching science by reinforcing this kind of pedagogical content knowledge.

  • 148.
    Andersson, Kristina
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Biology.
    Gullberg, Annica
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, Biology.
    Hussénius, Anita
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    Scantlebury, Kathryn
    Department of Chemistry and Biochemistry, University of Delaware, USA.
    "We do science, we don't do gender!" Challenging science teaching education: Gender awareness in contructing knowledge of science and science teaching2015In: Feminist Pedagogy in Higher Education : Critical Theory and Practice / [ed] T. P. Light, J. Nicolas & R. Bondy, Waterloo, ON, Canada: Wilfrid Laurier University Press , 2015Chapter in book (Refereed)
  • 149.
    Andersson, Kristina
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Gustafsson, Christina
    University of Gävle, Faculty of Education and Business Studies, Department of Culture Studies, Religious Studies and Educational Sciences, Curriculum studies.
    Methodological dilemmas in action research2011In: Educational action research, ISSN 0965-0792, E-ISSN 1747-5074Article in journal (Refereed)
    Abstract [en]

    In this study we want to call attention to and discuss two aspects of importance for work toward change regarding fundamental values through action research. The first aspect is time, and taking it into account according to “the action research spiral”. The second aspect concerns the importance of critical events for making progress and challenging preconceived notions. We also stress that researchers as “outsiders” have the opportunity to overview the process in a way that the other participants (insiders) do not. The empirical data is collected from an action research project on science and gender conducted inSweden with teachers from preschool and K-6. The collaboration was proceeded during 2005 to 2010, a total of 57 months.   

  • 150.
    Andersson, Leo
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences.
    Lägets betydelse för värdet på småhus och tomtmark vid skidanläggningar2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to find out if vicinity to alpine ski resorts affect the transfer prices of properties. The study should also describe and analyse whether the taxation level of singel-family house properties close to a ski resort should be managed through value area divisions. The study is written on behalf of Lantmäteriet.

    In Sweden, the land is divided into various large properties. Each property is unique, which means that they have different values. The most important factor for the property’s tax assessment value is its geographical location. If the property is far from the community with poor communications to a nearby city, it probably has a low property value. If the property on the other hand has good communications, close to shops, schools and access to municipal water and sewage, it probably has a higher property value. In order to investigate this, two local price surveys on two alpine ski resorts has been done, Björnrike and Lofsdalen in the municipality of Härjedalen. Data on sales has been collected for each area, which has been analysed and processed into the result of this study. Interviews have also been done in the study.

    The study shows that there is a connection between family-house properties that have ski-in/ski-out location and the tax assessment value. Properties that have this location are sold for a higher purchase price than the properties that do not have a ski-in/ski-out location. This study has only investigated how the ski-in/ski-out location affects the market value of properties in Björnrike and Lofsdalen. However, real estate agents from various alpine ski resorts in Sweden agree that the sales prices are higher for properties and condominiums with a ski-in/ski-out location.

    In Björnrike, the value difference is not significant enough in order to be managed through value area divisions. In Lofsdalen, on the other hand, family-house properties with ski-in/ski-out location should be handled with separate value area divisions. One suggestion that this study has resulted in, and which is reported in the discussion, is that family-house properties at alpine ski resorts could be handled in different location classes in relation to the ski slope and the ski lift. Based on the location class, the family-houses would then be assessed differently. The closer to the ski slope the property is located, the higher the location factor the property will have, which affects the tax assessment value.

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