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  • 1.
    aala, elsafei
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Numerical study of flow development in the near and intermediate field of a free round jet2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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    fulltext
  • 2.
    Aasa, Ulrika
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research. Department of Community Medicine and Rehabilitation, Physiotherapy, University of Umeå, Sweden.
    Jensen, B. R.
    Sandfeld, J.
    Richter, Hans
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Lyskov, Eugene
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Crenshaw, Albert G.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    The impact of object size and precision demands on fatigue during computer mouse use2011In: Advances in Physiotherapy, ISSN 1403-8196, E-ISSN 1651-1948, Vol. 13, no 3, p. 118-127Article in journal (Refereed)
    Abstract [en]

    Prolonged computer use, especially if fatigue ensues, is associated with visual and musculoskeletal symptoms. The aim was to determine the time-course of perceived fatigue in the wrist, forearm, shoulder and eyes during a 60-min mouse task (painting rectangles), and whether object size and/or mouse use demands were of influence. Also, we investigated performance (number of rectangles painted), and whether perceived fatigue was paralleled by local muscle fatigue or tissue oxygenation. Ten women performed the task for three conditions (crossover design). At condition 1, rectangles were 45 × 25 mm, square paint cursor size 1.3 × 1.3 mm, and mousepointer movement ratio 1:26. At condition 2, the same cursor size and mousepointer movement ratio was used, but rectangles were smaller. At condition 3, the smaller rectangles were used, but the cursor size was also smaller and mousepointer movement ratio was 1:8. The results showed increased self-reported fatigue over time, with the observed increase greater for the eyes, but no change in physiological responses. Condition 2 resulted in higher performance and increased eye fatigue. Perceived fatigue in the muscles or physiological responses did not differ between conditions. In conclusion, computer work tasks imposing high visual and motor demands, and with high performance, seemed to have an influence on eye fatigue. 

  • 3.
    Abad, Marta
    University of Gävle, Department of Technology and Built Environment.
    WORK WITH AGENDA 21 IN EUROPEAN CITIES.: A case of study: the waste's management in Barcelona and Gävle2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    Sweden is a long-term world reference country in terms of sustainable development. On the other hand, Barcelona has recently made great efforts in order to improve and to make society aware of the importance of environmental issues. Hence, it would be interesting to investigate if these efforts had succeeded in the waste’s management in Barcelona compared to other leading European cities, and particularly to the case of Gävle.

    In this work, the operation of the management of the urban solid wastes of the two cities is explained.

    First, the objectives marked by Agenda 21 of each locality are exposed. Next, a theoretical perspective about management, generation of wastes and types of waste treatment is provided. In the following chapter, the results of the generation of wastes, selective collection and the treatments of the wastes are shown for both the cases of Barcelona and Gävle until the 2006.

    Finally, the two cities are compared and the results obtained in the management of the wastes are discussed.

    The conclusion in this study is that Barcelona has improved noticeable in terms of environmentally safe management of the wastes. This has happened thanks to the efforts of the city council and of the citizens.

    But It is still necessary to make a major effort by the inhabitants of Barcelona.

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    FULLTEXT01
  • 4.
    Abbas, Syed Haider
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Enhancement of Viterbi Decoder2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
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    Thesis-report
  • 5.
    Abbas, Wasim
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Asghar, Imran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    The Role of Leadership In Organizatinal Change: Relating the successful Organizational Change with Visionary and Innovative Leadership2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The globalization has converted the world into a small global village; a village in which there is an ever high stream of contentions and competitions between organizations. In this scenario the most effective and beneficial maneuver for any organization is to create innovative ways in conducting business. This thesis deals with the role of leadership in the phenomena of organizational change and innovation. The leader as a person in charge or as a change agent can manage an organization or the process of organizational change more effectively and successfully if h/she is capable and competent. Rapid technological advancements, high expectations of customers, and ever changing market situations have compelled organizations to incessantly reassess and reevaluate how they work and to understand, adopt and implement changes in their business model in response of changing trends. Organizational change is a demand of the day, and needed for organizations to survive. Organizations now a days, well understand the importance of the matter, and are serious to prepare themselves not only the current, but also for the future trends to get the level of sustainable success, but Along with all of its implications and importance the process of organizational change is also a very complex and challenging.  Research shows that 70 percent of organizational changes fail to get their goals. As leadership has a central role in evolution and cultivating an organization, the process of organizational change demands a very effective and highly competent leadership that is well capable to perceive the most desirable shape of an organization and address the issue of organizational change in most appropriate way. The analysis of literature reviewed and the results of real life cases of organizations which are studied for this thesis shows, that a leadership with the competencies of “Vision” and “Innovative Approach” along with other characteristics can prove more effective to conclude the complex phenomena of organizational change with success. Further the successful organizational change can leads to innovation for organization, which is the key of long term success and sustainability. This thesis as a result proposed a model which is derived from the leadership competencies, organizational change, and sustainable success and innovation literature. This model expresses relationship between successful organizational change and leadership on the basis of h/her characteristics, which are ‘Vision” and “Innovative Approach”. With the help of proposed model this relationship can be viewed graphically.

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    FULLTEXT01
  • 6.
    Abbasi, Mahdi
    University of Gävle, Department of Technology and Built Environment.
    Characterization of a 5GHz Modular Radio Frontend for WLAN Based on IEEE 802.11p2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The number of vehicles has increased significantly in recent years, which causeshigh density in traffic and further problems like accidents and road congestions.A solution regarding to this problem is vehicle-to-vehicle communication, wherevehicles are able to communicate with their neighboring vehicles even in the absenceof a central base station, to provide safer and more efficient roads and toincrease passenger safety.The goal of this thesis is to investigate basic physical layer parameters of ainter-vehicle communication system, like emission power, spectral emission, errorvector magnitude, guard interval, ramp-up/down time, and third order interceptpoint. I also studied the intelligent transportation system’s channel layout inEurope, how the interference of other systems are working in co-channel and adjacentchannels, and some proposals to use the allocated frequency bands. On theother hand, the fundamentals of OFDM transmission and definitions of OFDMkey parameters in IEEE 802.11p are investigated.The focus of this work is on the measurement of transmitter frontend parametersof a new testbed designed and fabricated in order to be used at inter-vehiclecommunication based on IEEE 802.11p.

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    FULLTEXT01
  • 7.
    Abdalla Mohamed Ahmed, Fayad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energy Audit in Educational Buildings: Case study of Fridhemsskolan in Gävle2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The global share from buildings towards energy usage in residential and commercial buildings have been increasing constantly reaching between 20% to 40% in developed countries and has overtook the other major sectors: industrial and transportation. Energy demand reduction in the building sector is important for Sweden to achieve national energy aims for reduced energy use in the future.  For this reason, energy efficiency measures in buildings today is one of the main objective for energy policy towards 2020 goals.

     

    This project moves on the same path to find energy efficiency potential in Fridhemsskolan buildings in Gävle, Sweden by performing energy audit using IDA-ICE software to simulate energy performance for the buildings under study. In addition, measurements have been made on three of the school buildings named Hus 1, Hus 2 and Hus 3.

     

    The results include different energy efficiency retrofits on each building and economic analysis of these retrofits for each building individually and for the whole buildings together. The presented measures are reducing working hours of the ventilation system in Hus 2, change of CAV system with VAV system in (Hus 1 and Hus 2) and lights changing to LED, s efficient lights and building envelope improvement which includes walls and roof extra insulation and windows replacement.

     

    Replacement of the CAV system in Hus 1 and Hus 2 were not economically beneficial when considering their high cost compared to energy reduction that can be achieved by applying them. On the other hand, energy retrofits analysis showed that combination of the following energy efficiency measures is the most effective and profitable: extra insulation (walls and roof), windows replacement and lights change to LED in the three buildings. In addition to these measure is reducing running hours of the ventilation system in Hus 2.

     

    Implementation of the recommended energy efficiency measures will save 120, 737 kWh/ year of the district heating and 21, 962 kWh/year electricity consumption with capital investment of 417, 396 SEK and 98, 957 SEK/ year cost saving with payback period of 4.2 years. These figures represent 40.3% and 18.1% reduction in district heating and electricity energy use respectively.

     

    Since reducing working hours of ventilation system measure has no capital investment and have the highest figure of energy reduction it reduces payback period significantly. In case the amount of money saved by this measure doesn’t consider; payback period for the other measures which require capital investment will be 13.5 years and the energy saving in terms of cost will be 30, 874 SEK/ year. 

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  • 8.
    Abdalla, Shireen
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Strömlind, Sandra
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Den ekonomiska lönsamheten att friköpa en tomträtt: En studie angående tomträtter i Gävle kommun2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Site-leasehold right is a form of access to a property. This means that the owner of the property, usually a municipality or the state, let a site-leaseholder use the property against an annual ground rent. A ground rent is determined by a site-leasehold agreement between the owner of the property and the site-leaseholder. The fixed ground rents are for a period of 10 or 20 years. Long periods of rents combined with a real estate market with rising prices means that the ground rent at a new period of ground rent can be increased considerably. The site-leaseholder may well choose to redeem their long lease. To buy the freehold of a site-leasehold means that the site-leaseholder acquires the property of the property owner and form a new single-family real estate.  The purpose of the study is to provide a better understanding and knowledge of the site lessee facing the decision to retain the site-leasehold or redeem it. The goal of the project is to provide knowledge about when the economic viability of redeeming a siteleasehold may be deemed attained. Another goal is based on the site-leaseholders perspectives consider to highlighting the underlying reasons why a single-family siteleasehold redeemed.   The study is limited to detached single-family site-leaseholds in three geographical areas in the municipality of Gävle. The economic viability of redeeming single-family site-leasehold examined from the site-leasehold executiver's decision to sell or retain the site-leasehold. To examine more closely why a site lessee chooses to redeem the siteleasehold conducted qualitative telephone interviews.  From the results based on the study, it can be concluded that it is likely to be economically justified to redeem a single-family site-leasehold on the price of acquiring the plot is equal to or less than the amount that symbolizes the breaking point of economic viability. Of the respondents surveyed for the study the single biggest reason for why a site lessee chooses to redeem his site-leasehold was because of the uncertainty arising from the developments around the ground rent.

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  • 9.
    Abdalmunim, Rand
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Effektivisering av bygglovsprocessen gällande ändring av kulturhistoriskt värdefull bebyggelse: En fallstudie av ett miljonprogramsområde-Nya Nordostprojektet i Gävle2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En stor del av Sveriges bebyggelse har byggts mellan 1965 och 1974 eftersom det rådde stor bostadsbrist i Sverige. Regeringen beslutade att en miljon bostäder skulle uppföras under denna tid, det s.k. miljonprogrammet. Det byggdes bostäder i varierande former och storlekar för att bygga bort bostadsbristen. Storskaligheten och en stor grad av upprepning av identiska hus är kännetecken för miljonprogrammets bebyggelser. Nu är det dags att renovera dessa byggnader. I och med att dessa byggnader är av allmänt intresse då de speglar en del av Sveriges arkitekturhistoria ställer kommunerna vissa krav vid renovering av dem. Det kommunala företaget Gavlegårdarna i Gävle tar initiativ till att utveckla bygglovsprocessen för sådana bebyggelser. Detta görs för att reducera tiden för framställande av ett godkänt bygglov samt effektivisera och underlätta kommunikationen med kommunen under hela projektet. För att kunna bevara dessa byggnader i högsta möjliga mån har Gavlegårdarna utarbetat en effektiviseringsprocess genom att hyra in en extern bevarandeexpert för att fungera som en bro mellan företaget och kommunen samt för att kunna dela med sig av sina erfarenheter gällande bevarandet av det eventuella området. Dessutom har Gavlegårdarna låtit kommunen vara med från ett tidigt skede, d.v.s. redan från den första presentationen av förslaget. Därmed har kommunen fått vara med och medverka i förslaget, redan innan bygglovsansökan.

     

    Detta examensarbete tar upp konsekvenserna av de nya tillagda rutinerna och hur de har påverkat bygglovsansökningsprocessen för Nya Nordostprojektet. Genom att intervjua de inblandade aktörerna i det undersökta projektet har slutsatsen dragits att dessa rutiner har bidragit till att processen bedrivits mer effektivt jämfört med företagets tidigare projekt. Därutöver visar denna uppsats hur hyresgästerna har engagerat sig i det eventuella arbetet. Enkätundersökning har utförts för att kunna höra hyresgästernas åsikt.

     

    Det har visat sig att de nya rutinerna har effektiviserat tiden för bygglovsansöknings-processen. Tiden har förkortats jämförts med Gavlegårdarnas övriga projekt. Fördröjning i tid kostar företaget mer pengar. Dessutom har den förbättrade kommunikationen underlättat för båda parter att ta emot klagomål lättare och acceptera det. Det bidrar till att kommande problem kan lösas smidigare. Undersökningen har även visat att i projekt som Nya Nordost tas inte stor hänsyn till hyresgästernas åsikter, då byggherren redan är styrd från kommunen, vilket försvårar att flera kan vara med och välja. Ett annat resultat av denna undersökning var att de intervjuade personerna hade olika åsikter om bevarandet gällande Nordost. De flesta tyckte att Nordost ej var värt att bevara. Undersökningen visade även att hyresgästerna inte har engagerat sig lika mycket i bevarandet av gamla byggnader jämfört med att bo i ett modernare och nyrenoverat område.

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  • 10.
    Abdelrahman, Ahmed
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Detection and Extraction of Sky Regions in Digital Images based on Color Classification2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In many applications of image processing there is a need to extract the solid background which it is usually sky for outdoor images. In our application we present this solution. We developed an automatic algorithm for detection and extraction of sky regions in the color image based on color classification. In which the input image should be in the RGB color space and the blue color is detected and classified. Then the color image is transformed to the binary form and the connected regions are extracted separately. The connected regions are then sorted in a descending order according to the biggest area and the biggest region is identified. Then we merged all objects that have similar sky properties. Experimental results showed that our proposed algorithm can produce good results compared to other existing algorithms.

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    Sky_Regions_Extraction
  • 11.
    Abdi, Joan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences. Joan Abdi.
    Joel, Johansson
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Georeferering av ortofoto med UAV: En jämförelsestudie mellan direkt och indirekt georeferering2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    UAV (Unmanned Aircraft Vehicle) has revolutionized the creation of orthophotos with its contribution to increased safety, lower costs and more effective ways when making orthophotos. The traditional aerial photogrammetry with airplanes and placement of flight signals has been the standard method for years. To fly with UAV instead of an airplane is cheaper and saves time, however, the placement and measurements of flight signals is still time consuming and therefore expensive. The company DJI has developed a new UAV called Phantom 4 RTK that supports satellite based technology for direct georeferercing.

    This study compared two different measuring methods when producing orthophotos with UAV: direct georeferencing with NRTK (Network Real Time Kinematic) and indirect georeferencing when using different number of Ground Control Points (GCP). The study was conducted at the University of Gävle over an area of eight hectares. An investigation of the deviation in plane and height resulted in acceptable units based on the guidelines that were followed in HMK – Ortofoto and the controls that were followed from SIS- TS 21144:2016.

    The RMS value in plane for the indirect georeferencing method is 0,0102 m. For the direct georeferencing method the RMS value in plane when using ground control points is between 0,0132 and 0,0148 m. At last the RMS value for the direct georeferencing method without ground control points is 0,0136m. The RMS value in height is between the intervals 0,008-0,025 m.

    The data presented in this study show that an accepted quality in the orthophotos can be acquired based on the RMS values in plane and height for every georeferencing that was tested. After accomplished controls and evaluation the results show that the different georeferencing methods doesn´t differantiate too much from each other based on their quality. However, the direct georeferencing method with ground control points is more effective from a time perspective.

    Phantom 4 RTK is new on the market and more research is necessary in order to understand the potential of this technology and its posibility to integrate into society. More research is recquired for the direct georeferencing method in order to evaluate the quality of orthophotos.

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    fulltext
  • 12.
    Abdi, Shorash
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Stedt, Fredrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Utvärdering av Leicas multistations och laserskanners mätosäkerheter2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Presently there is no standard for the evaluation of measurement uncertainties for terrestrial laser scanner (TLS) despite the fact that the instrument has been on the market and used for a long time. Since the manufacturer's specifications do not always correspond with reality, it is important to have knowledge about how well the instrument performs. Numerous studies over the past decade have applied different approaches to estimate the measurement uncertainties on various TLS.

    The purpose of this study was to evaluate and compare the measurement uncertainties of the TLS Leica ScanStation C10 with the multi station Leica Nova MS50 under two different weather conditions. The uncertainty was calculated using ISO 17123-5:2012, which is an international standard developed for acquiring measurement uncertainties of total stations, to investigate whether this standard could also be applicable for TLS. The survey, which took place outdoor at the University of Gävle, was carried out by scanning targets that were set up in a triangle formation from three stations. Both spheres and HDS-targets were scanned with the TLS while the MS50 only scanned spheres. The targets were scanned four times from each instrument setup. Cyclone was used to find the coordinates on the center of the targets which were used to calculate the uncertainties according to the ISO-standard. The results showed that the 3D-uncertainty of C10 with HDS-target and spheres were 2.9 mm and 3.5 mm during sunny conditions and 1.1 mm and 1.4 mm during cloudy conditions, respectively. In the case of the MS50, the uncertainty was 3.0 mm during sunny and 3.7 mm during cloudy conditions. MS50 demonstrated a higher 3D-uncertainty in both weather conditions due to high uncertainty in the vertical direction. In addition, a chi-two-test carried out on the TLS showed that the calculated uncertainty in plane and height did not significantly deviate from the manufacturer's specified uncertainty when using HDS-targets during cloudy conditions. Furthermore, it was found in the F-test that there was a significant difference in plane and height between two scans with the same instrument and target type in different weather conditions. MS50 did not show any significant difference at all. The results of this study showed that there will be a significantly lower uncertainty when scanning in cloudy conditions. Our conclusion is that it is possible to apply the standard to calculate the measurement uncertainties on TLS and ISO should consider using the same standard for TLS as the total station.

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    Utvärdering av Leicas multistations och laserskanners mätosäkerheter
  • 13.
    Abdul Hakim, Faisal
    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.
    Said, Shazad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    En studie av småhusentreprenader: Varför går det fel?2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to investigate the single-family home construction industry and what problems arise. Furthermore, it was intended that this study would give the public a better idea of why conflicts arise between customers and contractors and how home suppliers work to counteract these problems.

    To achieve the purpose and get answers to the research questions, we used a qualitative research method in the form of semi-structured interviews. The reason why this interview technique was applied was to give respondents the freedom to talk openly about their experiences and views. The respondents interviewed were four representatives of house suppliers, three clients, a building inspector and an inspection manager.

    The results of the interviews showed that there was a common opinion among clients and house suppliers on certain issues, but then there were also opinions that differed. The study showed that customers experience the construction of detached houses as a slow and energy-intensive process. The problems that are common in detached house contracts are that there is a difference in language and knowledge between the involved parties. This results in a lack of communication which in turn can lead to various conflicts.

    Home suppliers are aware of the problems that exist in the industry and work continuously to develop solutions. One such solution is to place great emphasis on documentation and contracts because they are the ones that are legally binding. The conclusion of this study was that good communication results in fewer misunderstandings and conflicts. Conflicts, on the other hand, cannot be completely avoided, but will always arise due to human factors. 

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    fulltext
  • 14.
    Abdulkarim, Israh
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering.
    Ledarskap och hälsofrämjande processer i detaljhandelssektorn: Fallstudie2020Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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    fulltext
  • 15.
    Abellán Guallarte, Alejandro
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Energy analysis between traditional hot water circulation system and an innovative pipe-in-pipe system2022Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    We are at a time when energy efficiency and the reduction in the use of non-renewable energy is an important objective in all aspects and will continue to be so, therefore it is necessary to try to reduce energy and heat losses in the systems used in homes and, in particular, in the domestic hot water (DHW) system. This study aims to find out the advantages and disadvantages of an innovative pipe-in-pipe (PIP) system for DHW circulation with respect to the conventional system of two separate pipes. Previous studies have shown that DHW circulation is indeed an important point of energy losses in the home and that it is possible to reduce these losses by using the innovative system under study. The properties and coefficients defining the heat transfer system have been obtained for both the traditional and innovative systems by using empirical equations and iterative processes, indicating a 32% reduction in heat losses in favour of the pipe-in-pipe system. However, this result has been obtained in a kind of case study, using some simplifying assumptions, needed to accomplish to work within limited time. So the result could vary if a somewhat different system is studied, which is why it is necessary to carry out further studies and research on this subject in order optimize DHW systems in buildings.

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  • 16.
    Abeyrathna, Nuwan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering. KTH.
    Design and Construction of a Supervisory Control and Data Acquisition System for full scale combustion test facility2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One of major concerns in gas turbine industry is to reduce emissions.  Tow kind of approaches could be identified in the industry to reduce emissions, namely Primary Emission Reduction approach and Secondary Emission Reduction approach. The primary approach concerns emission prevention in combustion, while secondary approach is all about emission cleanup before releasing to the atmosphere.

    Combustion flame temperature highly influences on emissions specially NOx formation.  NOx emission is lower when the combustor operates close to lean flammability limit. Incorporating catalyst to combustor is one of methods to extend flammability limit.  Heat and Power Division at KTH-Royal Institute of Technology in Sweden has developed a test facility to test performances of catalyst in combustion.

    The combustion test facility available at Heat & Power Davison at KTH, consists of high pressure air compressor and air flow control system, air preheating unit and control system, fuel flow control system, combustor unit, and exhaust gas analyzer system. But lack of proper user interface to control and monitor the operation of the test facility through a computer work station was a major concern from experimenters.

    The purpose of the thesis work is to design and construction of supervisory control and data acquisition system for the full scale catalytic combustion test facility.  Labview 2012 is used as the main platform for implementing data acquisition and control system for the test facility. Thermocouples, pressure transducer signals, air flow meter signal are connected to Keithley 2701 data acquisition system and then connected to the computer. Fuel flow controllers are directly connected to the computer via serial port. Air flow control actuator signal is given through ADAM digital to analogue converter.

    Developed GUI is more convenient for users in terms of easy control of air flow, fuel flow and gas sampling probe systems, and monitoring of temperature, pressure measurements and exhaust gas species systems. And also GUI provides web interface to select correct conversion factor, and also to view live data recording. The developed GUI can be accessed through online to monitor the operation. 

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    EGI Thesis report_Nuwan Abeyrathna_Final
  • 17.
    Abeywardana, Asela Janaka
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Solar - Biomass hybrid system for process heat supply in medium scale hotels in Sri Lanka2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study aimed at evaluating and demonstrating the feasibility of using Concentrated Solar Thermal technology combined with biomass energy technology as a hybrid renewable energy system to supply the process heat requirements in small scale industries in Sri Lanka. Particularly, the focus was to apply the concept to the expanding hotel industry, for covering the thermal energy demand of a medium scale hotel.

    Solar modules utilize the rooftop area of the building to a valuable application. Linear Fresnel type of solar concentrator is selected considering the requirement of the application and the simplicity of fabrication and installation compared to other technologies. Subsequently, a wood-fired boiler is deployed as the steam generator as well as the balancing power source to recover the effects due to the seasonal variations in solar energy. Bioenergy, so far being the largest primary energy supply in the country, has a good potential for further growth in industrial applications like small hotels. 

    When a hotel with about 200-guests capacity and annual average occupancy of 65% is considered, the total annual CO2 saving is accounted as 207 tons compared with an entirely fossil fuel (diesel) fired boiler system. The annual operational cost saving is around $ 40,000 and the simple payback period is within 3-4 years. The proposed hybrid system can generate additional 26 employment opportunities in the proximity of the site location area.  

    This solar-biomass hybrid concept mitigates the weaknesses associated with these renewable technologies when employed separately. The system has been designed in such a way that the total heat demand of hot water and process steam supply is managed by renewable energy alone. It is thus a self-sustainable, non-conventional, renewable energy system. This concept can be stretched to other critical medium temperature applications like for example absorption refrigeration. The system is applicable to many other industries in the country where space requirement is available, solar irradiance is rich and a solid biomass supply is assured.    

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  • 18.
    Abhary, Kazem
    et al.
    University of South Australia, Adelaide, Australia.
    Kovacic, Zlatko
    The Open Polytechnic of New Zealand, Lower Hutt, New Zealand.
    Lundberg, Sven-Erik
    Association of International Roll Pass Designers and Rolling Mill Engineers, Dortmund, Germany.
    Narayanan, Ramadas
    Central Queensland University, Bundaberg, Australia.
    Spuzic, Sead
    University of South Australia, Adelaide, Australia.
    The application of a hybrid algorithm to roll pass design2015In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 79, no 5-8, p. 1063-1070Article in journal (Refereed)
    Abstract [en]

    Human–computer interface was utilized to amplify the power of a hybrid algorithm that combines fuzzy logic, regression analysis, and non-linear optimization to extract knowledge from a roll pass design database. This strategy is applied to grooves with vertical and horizontal symmetry which are employed in initial passes to roll a broad range of steel products. The results presented here from the case study are both statistically significant and valid from the viewpoint of roll pass design theory. © 2015, Springer-Verlag London.

  • 19.
    Abid, Muhammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production. KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management.
    Global Supply Chain Design: Exploring configurational and coordination factors2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis addresses the topic of global supply chain design. One major challenge concerns how to manage the tension between separation and integration pertaining to the localization of business activities. In this regard Ferdows (2008) worked to create two new production network models (rooted production network and footloose production network). Earlier studies have highlighted the choices that are involved in the network of facilities but lack in providing a comprehensive picture in terms of both configurational and coordination factors that govern the design of global supply chain. There is a need for a conceptual model where factors affecting the design process of a global supply chain can be applied. Two main research questions have been addressed in this study. First, exploring and identifying the factors affecting global supply chain design. Second, investigating the factors that influence the position on the spectrum of rooted and footloose supply chain design.      

    A literature review analysis and multi-case studies have been performed for this study in order to explore the factors. The companies were selected in order to reflect upon the two types of network, i.e., rooted and footloose. The primary data were selected through interviews with the managers.

    This study highlighted that there are many factors that affect configurational and coordination decision areas within a global supply chain. This study categorized the factors and the configurational/coordination decision areas with two main competitive priorities, i.e., cost and differentiation in the form of a “conceptual model.” The study also highlighted the factors in a matrix, which showed their position on the spectrum of rooted and footloose network configurations. For instance, the coordination factors that drive towards a footloose network include: high orchestration capabilities, need access to new technology and knowledge, proximity to suppliers, etc. The configurational factors that drive towards a rooted network include: economic stability, proximity to market, concerns for sustainability issues, high transportation cost, need for high proximity between key functions, need for intellectual property rights protection, etc.

  • 20.
    Abid, Muhammad
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation.
    Relationship between competitive priorities and global supply chain design: A conceptual frameworkManuscript (preprint) (Other academic)
  • 21.
    Abid, Muhammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Bengtsson, Lars
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Dabhilkar, Mandar
    Stockholm University, School of Business.
    Factors affecting shifts in global supply chain networks: A configurational approach2013In: Proceedings of the 20th International Annual EurOMA conference, Dublin, Ireland, 9-12 June 2013, 2013Conference paper (Refereed)
    Abstract [en]

    In certain situations, global companies strive to take advantage of short-term changes in economic and exchange rates on the never-ending journey of competitiveness. This paper seeks to extend Ferdows’s (2008) production network models by adding the factors affecting shifts between rooted and footloose network configurations. Two companies were selected in order to illustrate the models and reveal other possible factors. The identified factors are differentiated in terms of configuration and coordination and merged in a matrix. The trends and implications on global supply chains are also discussed. 

  • 22.
    Abid, Muhammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Bengtsson, Lars
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Hellberg, Roland
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Dabhilkar, Mandar
    KTH Royal Institute of Technology, Department of Industrial Economics and Management .
    Factors affecting global supply chain design2012Conference paper (Refereed)
    Abstract [en]

    Due to the limited existing knowledge pertaining to the factors which govern localization of operations and capabilities in a global supply chain, the purpose of the paper is to find out which factors and how they jointly affect the design of global supply chains. The relevant literature is reviewed and a concept matrix is developed. Five companies were selected in order to illustrate the issues of global supply chain design. Among them, three companies are considered to have efficient supply chain and less complex products, while the two others are considered to have responsive supply chain and more complex products. The issues discussed with the selected companies cover global sourcing, challenges, technological advancement and issues related to management control. The study identifies about fifty factors that affect global supply chain design, and specifically how theses relate to design decisions on location of factories and production, supplier selection and development, distribution of products and organisation of interfaces along the supply chain. The discrepancies between theory and practice as well as the implications for further research are discussed.

  • 23.
    Abid, Muhammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Bengtsson, Lars
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Hellberg, Roland
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Mandar, Dabhilkar
    KTH Royal Institute of Technology, Department of Industrial Economics and Management .
    Global supply chain design: Building a decision model2012Conference paper (Refereed)
    Abstract [en]

    The knowledge pertaining to the factors, which govern localization of operations and capabilities in a global supply chain, is limited. The purpose of the paper is to find out which factors and how they jointly affect the design of a global supply chain. The relevant literature is reviewed and a concept matrix is developed. The study identifies 30 factors that affect a global supply chain design and specifically how theses relate to the design decisions on location of factories and production, supplier selection and development, distribution logistics, organisation of interfaces/enterprise information infrastructure along the supply chain and human resource development. The decision model is developed and the description of the model is done with the help of an example (location of a factory) by using the Analytical Hierarchy Process (AHP) (Saaty, 1990).  

  • 24.
    Abolghasemi Kordestani, Arash
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för industriell ekonomi.
    Farhat, Farshad
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för industriell ekonomi.
    Supply Chain Maturity and Financial Performance: Study of Swedish SMEs2009Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Purpose - The goal of this research is to demonstrate that financial performance of current year is dependent to the amount of maturity of the supply chain processes. This aim is achieved through considering current supply chain process maturities of the firm together with financial performance of prior years.

     

     

    Research question - How supply chain process maturities in relation to financial performance of prior years are related to current financial performance  

     

     

    Methodology - The deductive approach has been followed to use theories and literatures to build the hypothetical model in order to test it empirically.

    This quantitative research is benefited from the primary data of Swedish steel SMEs including the secondary data from financial ratios from Scandinavian financial database

     

     

    Findings - The effect between supply chain process maturity and current year financial performance, the effect between prior year financial performance and current year financial performance, and also total effect of prior year financial performance and supply chain process maturity on current year financial performance proved empirically.

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  • 25.
    Abolghasemi Moghaddam, Saman
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    The effects of low-emissivity window films on thermal comfort and energy performance of a historic stone building in cold climate: computer simulations with "IDA ICE"2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Low-emissivity (low-E) window films are designed to improve the energy performance of windows and prevent indoor overheating by solar radiation. These films can be applied to different types of glazing units without the need for changing the whole window. This characteristic offers the possibility to improve the energy performance of the window of old and historic buildings for which preservation regulations say windows should remain more or less unchanged. This research aims to figure out to what extent a low-E window film can improve thermal comfort and energy performance of an old three-storey historic stone building in the cold climate of Mid-Sweden. In this research, first, with help of the simulation software “IDA ICE”, the entire building was modelled without window films in a one-year simulation. Second step was to add the low-E window films (3M Thinsulate Climate Control 75 (CC75)) to all the windows and repeat the simulation. Comparison between the results of the two cases revealed an improvement in energy use reduction as well as the thermal comfort when applying the films. For the application of the window films, a cost analysis using payback method was carried out which showed a long- time payback period. Although an investment with a long-time payback period is considered as a disadvantage, for historic buildings with very strict retrofit regulations specially when it comes to the building’s facades, application of the low-emissivity window films for better energy performance and thermal comfort is among the recommendable measures, but not necessarily the best.

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  • 26.
    Abou Raas, Mhd Jihad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Wall Compensation Algorithms for M-sequence UWB Radar2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A technique for wall compensation in the ultra-wideband (UWB) through-wall imaging radar is presented. The UWB system can be utilize in high precision measurements, but due to phase distortion and amplitude attenuation caused by the wall the precision is limited, the target is displaced, and the image is defocused. 

    In order to mitigate the wall effects, two methods are applied in this project. First, the unknown wall transfer function is estimated using real data measurements to design the inverse filter. Secondly, FIR Wiener filter is designed to improve the received m-sequence. After all, each method is tested using three parameters, the signal to noise ratio (SNR), the signal to clutter ratio (SCR), and the relative position error (RPE). 

    The inverse filter can eliminate the wall effects very well; it could correct not only the position of the target but also the image defocus. The new method can give improve the image quality and that can extend the use of UWB radar in many applications. 

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  • 27.
    Abraham, Yoseph
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science.
    Development of Advanced X-ray Micro-Tomography Helical Scan andTomographic Data Processing2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Micro-computed tomography (Micro-CT) is an imaging technique that allows for high-resolution,three-dimensional (3D) internal visualization of small objects in a non-destructive manner. However,a significant limitation arises when attempting to image elongated samples at higher resolutions andmagnifications due to the inherently small field of view (FOV). This thesis project introduces anapproach aimed at overcoming this limitation by combining helical scanning with the utilization ofthe open-source Astra Toolbox. The toolbox provides flexible scanning geometry parametrizationand facilitates tomographic reconstruction using the Feldkamp-Davis-Kress (FDK) algorithm.Helical data scanning represents a departure from traditional data acquisitions. Instead ofcapturing data at a fixed height, helical scanning acquires data by rotating and translating theimaged sample. This acquisition process extends the effective FOV, enabling the reconstruction oflarger samples. To illustrate this approach, a micro-CT helical scan was performed on a pencil asan elongated sample and compared with a conventional circular scan.While Micro-CT is a powerful imaging tool, it faces challenges when imaging weakly attenuating materials with hard X-rays. X-ray radiation possesses both amplitude and phase components,but conventional CT can only capture intensity information. This limitation often leads to poorcontrast in images of weakly absorbing samples. To address this issue, the project also designedpost-processing software to enhance CT image quality through phase retrieval. Phase informationprovides better contrast for small structures of weakly absorbing materials compared to intensityalone. The Paganin phase-retrieval algorithm is employed to retrieve this phase information, resulting in improved contrast-to-noise ratio (CNR) in tomographic reconstructions and subsequentsegmentation. As a result, the generated images exhibit sharper delineations and offer a morecomprehensive representation of the sample’s internal structure, especially after 3-D rendering.In summary, in this thesis, I designed the micro-CT procedure both from acquisition with anadvanced helical scanning technique and from a post-processing point of view through designingsoftware with a phase retrieval algorithm. The project has improved the conventional microCT intwo aspects, namely the field of view and the phase contrast. 

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  • 28.
    Abrahamsson, Emilie
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Relationen mellan kalkyleringsmetoder, Lean och produktionsflöden av kundanpassad karaktär: Hur kostnadsprecisionen i förkalkyleringen i denna typ av produktion kan ökas samt vilken kalkyleringsmetod som passar bäst2015Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    Since the manufacturing industry is heading for a higher level of customization and implementation of Lean, at the same time as outmoded traditional costing methods is still used in modern industrial organizations, it is interesting to explore the relations between production flows of customized character, Lean and different costing methods.

    The purpose of this thesis is to increase the cost precision in the preliminary calculation for a product flow of customer adapted and Lean character, and to describe a generalizable work process for this. The purpose is also to develop general recommendations regarding the choice of costing methods by, on a basis of the character of this production, a comparative analysis of costing methods (traditional costing methods, ABC and Lean accounting/VSC). Through a literature study and a case study of a production flow with a high level of variety and influence from Lean, both of the purposes has been fulfilled.

    The case study has been accomplished through interviews and observations. Problems and positive elements that according to literature characterize the production of customized products have also been found in the case company. That connection has been used to support the analysis of the relations. The relations between costing methods, Lean and production flows of customized character has been analyzed through a comparison between findings in literature and results from the case study. It has been found that Value Stream Costing (VSC) is the most appropriate costing method for production flows of customized products that has reached a high maturity level of Lean.

    The preliminary costing is dependent on reliable operation times which have been produced on the case study company, while a general work process has been developed. The operation times were in this case identified through video recordings of the production moments and a following analysis in the software AviX. By following the general work process that has been developed, useful material for preliminary costing and continuous improvements in the production flow will be obtained.

    Since research is showing that Lean should be implemented in the whole organization if full advantages of Lean shall be obtained, VSC is found to be an ideal costing method to replace outmoded, traditional costing methods at the same time as this costing method simplifies costing in production flows of customized character.

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  • 29.
    Abrego peris, Iñaki
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Antenna with medical applications for tumour cancer: hyperthermia function2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The idea is to improve or help the treatments that exist in the market in the medical field. Treatments such as mammography or radiotherapy make use of X-rays. X-rays are electromagnetic radiation in a high frequency band, this type of electromagnetic is dangerous to health because ionizing radiation is used, ionized atoms interact with matter. For this reason, in our work we give alternative solution to these treatments without any risk to health. This project consists in the use of non-harmful frequencies such as microwave. In this way, we will make an antenna with medical applications whose frequency range will be between 300 MHz and 30 GHz, specifically between 950MHz and 2.45GHz (medical range). The first step will be the detection of the tumour and classification of this, but our work is about another technique called hyperthermia. This technique consists in increase the temperature with a value of 40-43 degrees in the tumour area. Tumour resistance decreases when heat is applied to this. When combining a treatment with oncologic hyperthermia, the effect of radiotherapy is most effective (between 1.5-5 times). The most important part is study antenna in body tissues characteristics as SAR, depth penetration and antenna size; this theory part is essential to know the best parameters and what case use this. In work development we will choose and design antennas for the different parts of the body in some specific frequencies and choose circular antennas in frequencies of 915 MHz and 1.8 GHz. Finally, we will take measurements about temperature increase with meat and say some conclusions.

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  • 30.
    Abu Sulaiman, Iyad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Ibrahim, Miran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Framställning av dränerande bärlager från bergtäkt2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Bearing layers are used in road and building constructions as underlying soil layers to provide stability and support to the top layer that takes up the load. A normal bearing layer contains different amounts of materials such as stone, gravel, and filler. That mixture of materials contains a large amount of filler to give the product tightness and stability. Draining bearing layers usually contain less filler than ordinary bearing layers, because their purpose is to improve the drainage properties and reduce the risk of damage due to water collection.This thesis work took place at NCC's quarries in Sälgsjö and Hammarby. At NCC's rock quarry, there already is a standard bearing layer with a grain size of 0/32 and a filler content of approximately 4–5%. In this degree project, a production process has been created to obtain a drain bearing layer where the filler content is reduced to approximately 2–3%. The requirement for a draining carrier layer is 2–3% filler content and this requirement has been followed in this production process. The draining bearing layer has been produced based on a standard product with the same grain size.There are practical limitations in how the operations work and what capabilities are required. Moisture in the material has also been a limitation. In this project, work is done with freshly crushed material, which has a relatively low moisture content (1–2%). A vibration-free screen like the function of the harp has been designed and built. Then the standard product was run through the harp at different gradients and the new product was analyzed in the lab to see what filler content was achieved. A simulation test was performed using a FEM design program called Digiroad at Chalmers University of Technology in Gothenburg.The results demonstrate that the utilization of the developed models of harp screens reduces the proportion of filler in the material. Additionally, the conducted harp screen analyses confirm that the designed harp screens are effective in transforming a standard bearing layer into a draining bearing layer, which helps to prevent water accumulation under roads or buildings and thus reduces the risk of damage and problems. The efficient production process for producing draining bearing layers can be of great importance to ensure a sustainable and safe infrastructure.

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  • 31.
    Abugessaisa, Imad
    et al.
    Department of Medicine, Karolinska Institutet.
    Östman, Anders
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Testing-SDI: E-government Prospective, Requirements, and Challenges2011In: International Journal of Public Information Systems, ISSN 1653-4360, Vol. 2011, no 1, p. 11-47Article in journal (Refereed)
    Abstract [en]

    Spatial Data Infrastructure denotes the collection of technologies, policies and institutional arrangements that facilitate the availability of and access to spatial information. During the last few years the development of spatial data infrastructure in Sweden has been influenced by two actions. The first was the European Directive in spatial data infrastructure namely Infrastructure for Spatial Information in Europe (INSPIRE), and the second action was the Swedish parliament's directive early in 2008 on e-Government. In a modern society, spatial data play major roles and have different applications such as information support during disaster prevention and management. These two milestones involving Geodata development have created huge demands and represent great challenges for researchers in the area of spatial data infrastructure. One of these challenges concerned the methodologies involved for testing proposed data specifications from INSPIRE. This paper addresses the above challenge and introduces a framework for testing Geodata. The testing of Geodata includes, the testing of the data specifications for different geographical themes and data structure, the performance testing of Opengeospatial Web Services (OWS) and the usability of Geoportals and services. The proposed methods were evaluated during a pilot test for a regional geoportal in Sweden, and the reported results in this paper show the feasibility and applicability of the methods used. The methods used assisted in the identification of the performance related defects and the bottleneck involved in relation to the response time, stress and load. The methods support the detection of different types of errors that occur during the testing time such as http error, timeout error, and socket error. During the pilot test of a geoportal, it was discovered that the response time was 30 seconds which is 6 times higher than the INSPIRE required time (Maximum 5 second), with 500 virtual users accessing the system and performing a specific task. A usability test was conducted which focused on the users' acceptance and the “think aloud” methods. The usability testing enabled the identification of user-interface related problems and the results were quantified to enable comparisons to be made with current results and those from the new test.

  • 32.
    Abushaqfa, Omar
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Bakero, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Materials brandförmåga för mellanväggar2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays, architects, designers and engineers pay a lot of attention to fire safety in buildings.Due to the high number of accidents, fire safety in construction is becoming increasinglyimportant.In order to use more fire-resistant material in the structure, attention was paid to the propertiesof the materials used. The material has begun to be evaluated for standard resistance and somestandard tests have been developed. Based on how long the material did not show anysignificant damage, these materials were evaluated and graded. This classification can beaccessed from Eurocodes (Svensk trä,2022).Timber was used in construction even before history was written. Since the ancient civilization,wood has been an important building material.Wood exhibits great resistance to fire due to its self-insulating property.When wood burns, it first chars to a certain depth. Then the outer charred layer acts as a barrierand suppresses the fire. This fire-extinguishing property in itself is the wood's self-insulatingproperty. (Swedish wood, 2021).Fire exposure usually occurs according to the standard fire curve that describes a fullydeveloped fire as defined in EN 1363-1. Building parts must withstand fire for a certain time,for example 60 minutes. With wooden constructions, it is possible to achieve high fire resistancewith the help of insulating material (EI). (Swedish wood, 2021).In the first part of the thesis, the properties of wood as a building material are discussed. INthe next part discusses the fire classes Br0, Br1, Br2 and Br3 for buildings. After that, the readercan learn about how a building can be divided into sections depending on its fire rating. Amaterial investigation will be done to be able to see the fire properties of certain materials thatwe will add to or remove from the wall such as extra plasterboard or insulation material withoutchanging the thickness of the wall to make them more fireproof and to be able to last longerwithout the fire spreads to the other spaces with the help of better material ability. (Swedishwood, 2021).This work also presents the theory behind wall fire sectioning in terms of materials and thevarious fire engineering solutions with some examples of calculations relating to the fireresistance of the materials, with references to the instructions in SS-EN 1995-1-2:2004/AC:2010. Finally, the results are analyzed and compared with different materials. Usingthe results of reactions of different types of materials and insulation, the fire resistance ofwooden walls can be discussed in more detail.Results show that gypsum boards combined with stone wool is the best choice of material forcreating fireproof partition walls. The results of our calculations show that double gypsumboards on each side with a thickness of 15 mm combined with stone wool with a thickness of95 mm provides fire resistance up to 109 minutes. Compared to a partition wall with a gypsumboard on each side without insulation, fire resistance is up to 48 minutes. This has beenemphasized with a study where the fire resistance has been investigated for walls, they havefound that double gypsum board combined with stone wool with the right conditions providesfire resistance up to 142 minutes. However, it is crucial for fire resistance to work that theinstallation is carried out correctly. All resulting screws must be placed correctly, there must beno holes on the gypsum boards and the number of gypsum boards and insulation thicknesstogether with the correct assembly provides better fire protection. This is based on the resultsthat have been obtained from articles, calculation during this work and from interviews withthe companies that work with requirements, manufacture and installation of fireproof partitionwalls. 

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  • 33. Adams, Robin
    et al.
    Fincher, Sally
    Pears, Arnold
    Börstler, Jürgen
    Boustedt, Jonas
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Dalenius, Peter
    Eken, Gunilla
    Heyer, Tim
    Jacobsson, Andreas
    Lindberg, Vanja
    Molin, Bengt
    Moström, Jan-Erik
    Wiggberg, Mattias
    What is the word for 'Engineering' in Swedish: Swedish students conceptions of their discipline2007Report (Other academic)
    Abstract [en]

    Engineering education in Sweden – as in the rest of the world – is experiencing a decline in student interest. There are concerns about the ways in which students think about engineering education, why they join an academic programme in engineering, and why they persist in their studies. In this context the aims of the Nationellt ämnesdidaktiskt Centrum för Teknikutbildning i Studenternas Sammanhang project (CeTUSS) is to investigate the student experience and to identify and support a continuing network of interested researchers, as well as in building capacity for disciplinary pedagogic investigation.

    The Stepping Stones project brings together these interests in a multi-researcher, multi-institutional study that investigates how tudents and academic staff perceive engineering in Sweden and in Swedish education. The first results of that project are reported here. As this study is situated uniquely in Swedish education, it allows for exploration of “a Swedish perspective” on conceptions of engineering. The Stepping Stones project was based on a model of research capacity-building previously instantiated in the USA and Australia (Fincher & Tenenberg, 2006).

  • 34.
    Adeboye, Taiyelolu
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Robot Goalkeeper: A robotic goalkeeper based on machine vision and motor control2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report shows a robust and efficient implementation of a speed-optimized algorithm for object recognition, 3D real world location and tracking in real time. It details a design that was focused on detecting and following objects in flight as applied to a football in motion. An overall goal of the design was to develop a system capable of recognizing an object and its present and near future location while also actuating a robotic arm in response to the motion of the ball in flight.

    The implementation made use of image processing functions in C++, NVIDIA Jetson TX1, Sterolabs’ ZED stereoscopic camera setup in connection to an embedded system controller for the robot arm. The image processing was done with a textured background and the 3D location coordinates were applied to the correction of a Kalman filter model that was used for estimating and predicting the ball location.

    A capture and processing speed of 59.4 frames per second was obtained with good accuracy in depth detection while the ball was well tracked in the tests carried out.

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  • 35.
    Adis, Kurtalic
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Linkfire2011Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Planen var att konstruera en PCI-Express-till-PCI brygga för fyra MoCA radiokort. Problem uppstod då det visade sig att PLC8112 inte kunde hantera fyra PCI samtidigt som var utlovat från tillverkaren av bryggan. För att lösa problemet fick PCI6152 läggas till i designen. Det är en PCI-till-PCI brygga som också ska klara att hantera upp till fyra PCI enligt tillverkaren. Fyra MoCA radiokort förbrukar mycket ström. Två spänningsregulatorer lades till i designen för att kunna leverera de strömmar som krävs. För att säkerställa att radiokorten som ansluts till Linkfire inte blir för varma så placeras en temperatursensor under ett radiokort. Temperatursensorn har endast av/på lägen och till den ansluts två fläktar, därmed så betraktas dem som en fläkt då de inte är individuellt styrda.

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    Linkfire
  • 36.
    Afzal, Nauman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences. tet10nal@student.hig.se.
    Udata, Ramakrishna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences. tet10rua@student.hig.se.
    Designing and measurement of routing module for transceiver system at 3.125GHz2014Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    This report intends to impart a good understanding of routing modules used in modern transceiver systems. The radar system at RadarBolaget AB needed to have a good routing module for its newly designed transceiver antenna. In this report, studies have been done related to two majorly used routing modules in modern electronics industry; Microwave Circulator and RF/Microwave Switch. First off, different characteristics of routing modules are discussed. After having discussed important design parameters, practical design considerations for two routing modules are presented in a profound way. Theoretical knowledge for both of these two devices is presented in the beginning, followed by their practical designs using standard simulation software like HFSS and ADS. The report concludes its findings in a way that at the end of this report, reader becomes acquainted with ample information to be able to choose the best option available among all of the discussed designs. An FET RF Switch is chosen at the end of this project to be used for transceiver system which should be able to satisfy specifications specified by RadarBolaget AB. This project was carried out by two students of Master Program in Electronics/Telecommunications at Högskolan i Gävle in collaboration with RadarBolaget AB, Gävle, Sweden.    

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    Designing and measurement of routing module for transceiver system at 3.125GHz
  • 37.
    Afzali Gorouh, Hossein
    et al.
    Shahid Bahonar University of Kerman, Iran.
    Salmanzadeh, Mazyar
    Shahid Bahonar University of Kerman, Iran.
    Nasseriyan, Pouriya
    Shahid Bahonar University of Kerman, Iran.
    Hayati, Abolfazl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cabral, Diogo
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Gomes, João
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Karlsson, Björn
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Thermal modelling and experimental evaluation of a novel concentrating photovoltaic thermal collector (CPVT) with parabolic concentrator2022In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 181, p. 535-553Article in journal (Refereed)
    Abstract [en]

    In the present study, a zero-dimensional thermal model has been developed to analyze a novel low concentration photovoltaic-thermal (CPVT) collector. The model has been developed by driving heat transfer and energy balance equations for each part of the collector and then solving all the equations simultaneously. Moreover, a Monte-Carlo ray-tracing software has been used for optical stimulations of the parabolic trough solar collector. The novel CPVT collector has been experimentally tested at Gävle University (Sweden) and the model has been validated against the experimental results. The primary energy saving equivalent to the thermal-electrical power cogeneration of the CPVT collector has been determined. The effect of glass cover removal, heat transfer fluid (HTF) inlet temperature and mass flow rate on the collector performance has been investigated. The optimum HTF mass flow rates of the collector for maximum electrical yield and overall primary energy saving were determined under specified operating conditions by considering the pump consumption. The effect of mean fluid temperature on the thermal and electrical efficiencies has been studied and the characteristic equation of the thermal efficiency has been obtained. The thermal and electrical peak efficiencies of the collector have been found to be 69.6% and 6.1%, respectively.

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  • 38.
    Agbauduta, Stephen Ogba
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    SPATIAL MCDA FOR FINDING SUITABLE AREAS FOR HOUSING CONSTRUCTION2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Demand for residential houses in urban areas has become a major problem facing town planners today. With the high increase in urbanization due to the increase in population, residential houses are becoming more difficult to find. Planners aim at developing new ideas to combat the high increase in the demand for residential buildings. In recent times, different methods of analysis have been introduced that will help planners select best locations to erect residential houses.

    A Geographic information system (GIS) is one of the tools for analyzing and storing a great deal of information. Over the years, GIS technology has been introduced into planning and the result has been of great help to urban planners in planning sustainable environment for residents. This research aims at using GIS technology and multi-criteria decision analysis (MCDA) to determine possible locations to build residential houses and analyzing different methods of selecting suitability areas within the study area. An MCDA map was produced from the combination of different factors and constraint which include elevation, orientation of the building (direction), the soil type and land use type. Proximity analysis was also done to find out how infrastructures (existing roads, shopping malls and health care enter) are close to the study area. Results show that the southern, eastern, and a part of western side of the study area is better to build residential houses than other areas.

    Three different methods (visual interpretation method, seeding method and neighborhood method) where used to find out which method produces the most suitable locations within the study area. In order to calculate the suitability areas and suitability values, the sum of pixel values were calculated for each method. The visual interpretation method servers as a standard method of deciding the suitability area covers 15,375 m² and has the highest suitability values of about 500 pixels. The seeding method was used as an automatic method for selecting the suitability area; result shows that the suitability area covers 17,421 m² and has the highest suitability value of about 1200 pixels. The neighborhood method was calculated using two different statistics (mean statistics and majority statistics). The mean statistics covers an area of 12,439 m² while the majority statistics covers an area of 14,332 m². From analysis carried out, the seeding method is preferred for selecting suitability areas than the visual interpretation method and the neighborhood method but the visual interpretation method covers more suitability area than the seeding method and neighborhood method.

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    Agbauduta Ogba
  • 39.
    Agborsangaya, Etchu Oben
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Omoregie, Iyobosa Frank
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Does Culture Influence Decision Making in Project Teams?: A Multi Case Study in Sweden2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose: In the contemporary society in which companies operate there is increasing interest in understanding the effects and changes of culture on projects in connection to decision making. This is evident of the fact that most companies are using groups or teams composed of mixed culture to perform their tasks and develop their activities into different geographical regions by adopting project management as a “way of working” other than a tool or technique. The objective of this study is to explore the cultural influence decision making in project teams through a multi case study of applying Hofstede’s dimensions of culture model to selected Swedish firms. 

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  • 40.
    Ageborn, Elisabeth
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Cardenström, Caroline
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Acceptans hos närboende vid etablering av bygdeväg: En fallstudie av Sundsvall- och Timrå kommun2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the case of infrastructure projects, the authority should inform the nearby residents about what is happening in their area. Research shows that anchoring and trust are created when dialogues are applied in the planning process. These democratic processes are important to satisfy the interests of the public. The social aspect of a sustainable development is strengthened by allowing the public to participate in society's development, which in turn leads to greater equality. Changes create different reactions and communication has a significant role in the link between the public and authority, since information flows can contribute to less irritations and misunderstandings. An authority like the Swedish Traffic Authority not only has to deal with the public when establishing infrastructure projects, but also systems for planning processes, legislation, and financial frameworks. The purpose of this study is to investigate how the Traffic authority goes about giving out information to nearby residents in the planning process of new infrastructure and how the distribution of information affects the nearby residents' acceptance of the infrastructure project.

    A case study is carried out over two “2minus1” rural roads in Sundsvall and Timrå municipalities. For methods, questionnaires and interviews are used in studies, with the aim of collecting qualitative and quantitative data. Two methods are used to be able to verify results, as well as to get an overall picture of how the process works when establishing a “2minus1” road. Web-based questionnaires were sent to nearby residents at the two “2minus1” road, several interviews of nearby residents were conducted during site visits, and interviews were conducted with employees at the Swedish Traffic Authority who have expertise in establishing “2minus1” roads.

    The results of the interviews with the Swedish Traffic authority showed that there is no elaborate process for how they should distribute information to nearby residents when establishing a “2minus1” roads. This is because the “2minus1” roads are a new type of road and only a few of them have been established in Sweden. The results of the study indicate that information has a great importance for the acceptance of nearby residents. Acceptance is affected by when the information is distributed and whether the content of the information is adapted to the target group. By providing information on how the “2minus1” roads should be used and providing an understanding of the benefits of a “2minus1” roads, it contributes to greater acceptance by residents. Acceptance is a complex subject that can depend on many different factors. Acceptance is not only impact by information, but it can also depend on personal preferences.

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  • 41.
    Agebro, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Datormodellering av en värmelagrande betongväggs inverkan på det termiska klimatet i ett växthus2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes the building of a computer model that makes it possible to simulate the thermal climate in a greenhouse. The computer model is built on the physical theory of heat exchange that occur in a greenhouse, such as radiation and convective heat exchange. The model also includes the heat storage that is active in a greenhouse.

    The computer model is used to simulate the thermal climate in a greenhouse under three periods, winter, spring and summer. It also investigates which effect a concrete wall has on the thermal climate in a greenhouse. The purpose of putting a concrete wall in the greenhouse model is to investigate the possibility to store heat during the day and then use this heat when the temperature drops during the night.

    The result from the simulations shows that a concrete wall levels the big difference in temperature that normally occurs under a day in a greenhouse. It also shows that heat is stored in the concrete wall and during the night the wall temperature is higher than both the outdoor temperature and the greenhouse temperature. This makes the wall a source of heat during this time.

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    FULLTEXT01
  • 42.
    Agostini, Lara
    et al.
    University of Padova, Italy.
    Bengtsson, Lars
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Lazzarotti, Valentina
    Carlo Cattaneo University LIUC, Italy.
    Manzini, Raffaella
    Carlo Cattaneo University LIUC, Italy.
    Nosella, Anna
    University of Padova, Italy.
    Pellegrini, Luisa
    Stefan, Ioana
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Combining an external with an internal perspective on open innovation with scientific partners and patenting2017In: 18th International CINet Conference: Digitalization and innovation: designing the organization of the future, 2017Conference paper (Refereed)
  • 43.
    Agostini, Lara
    et al.
    University of Padova, Italy.
    Bengtsson, Lars
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Lazzarotti, Valentina
    Carlo Cattaneo University LIUC, Italy.
    Manzini, Raffaella
    Carlo Cattaneo University LIUC, Italy.
    Nosella, Anna
    University of Padova, Italy.
    Stefan, Ioana
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics. University of Gävle, Center for Logistics and Innovative Production.
    Open innovation with scientific partners and patenting: the moderating role of the internal context for innovation2017In: Proceedings of IFKAD 2017: Knowledge Management in the 21st Century: Resilience, Creativity and Co-creation, 2017Conference paper (Refereed)
  • 44.
    Aguilera, Rafael
    University of Gävle, Department of Technology and Built Environment.
    Implementation of a ceramic coating based upon the concept of emissivity2008Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 45.
    Aguirre Sánchez, Mikel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Air flow disturbance by moving objects at local exhaust ventilation2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The present thesis aims to study the effect of human movements on local exhaust ventilation.

    In its simplest terms, local exhaust ventilation is a system which has the function of extracting contaminated air situated close to the contaminant source, protecting a working person from exposure to hazardous substances by containing or capturing them locally, at the emission point. As an important security measure referred to terms of health, it is crucial for the healthiness of workers to control and prevent them from the exposure to vapour, mist, dust or other airborne contaminants. Additionally, to a lesser degree of significance, it can be stressed an expected increase in worker performance due to an improvement of the working conditions.

    There is an existing necessity for well-defined and appropriate methods to test the performance of local exhaust devices in order to reach standard efficiency values. The lack of an international standardization led to the realization of this study, which, ultimately, has the purpose of obtaining relevant results that can be utilized for future normalized test procedures.

    The study entails full scale experimental measurements that include air velocity measurements in 3 dimensions, a local exhaust ventilation device with circular hood and a flat flanged plate and a controlled generation of air turbulence through physical movements of a human-sized cylinder, simulating a walking person.

    The present study extends previous similar studies at the University of Gävle, where the controlled air turbulence was generated by a moving plate. After meaningful results obtained in that study, one of the considerations was to better simulate a walking person, by replacing the plate for a movable cylinder. The present study points at a larger similarity occurring with a cylinder than with a plate, as regards the air flow pattern produced by a real walking person.

    As in the previous study, the Percentage of Negative Velocities, PNV, has been used as the main measure of turbulence induced risk of contaminant spread. The PNV represents the fraction of the time when the flow is directed opposite to the suction air stream in front of the local exhaust hood. The obtained results conclude that the use of the cylinder as a moving object has been an improvement to simulate the effect of the movement of a human being on a relaxed walking pace.

    The present study was carried out in parallel with the thesis work by Leyre Catalán Ros, which complements this study by analyzing the effect of an added heated dummy, simulating a person seated in front of the local exhaust device.

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  • 46.
    Ahlin, Eddie
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Implementation and standardization of vibration measurements in strip production processes2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Within the era of the fourth industrial revolution the steel production industry is faced with demands of lower environmental impact and more cost-effective production are some of the challenges faced. To achieve more sustainable and efficient manufacturing processes companies try to digitalize and automate their production to a greater extent. Creating more robust, energy-efficient and adaptable solutions to increase the competitiveness of their company.

    This master thesis is about reverse engineering an existing solution for vibration measurements used at Alleima Strip. The goal was to create a new in-house solution for vibration measurements according to local programming standards using an ABB AC500v2 CPU paired with a FM502-CMS module. Using vibration measurements as a health indicator Alleima Strip hopes to progress their way of working with maintenance towards being more condition based.

    The result is a solution for vibration measurements customized for Alleima Strip. The report contains suggestions for improvements of the developed solution as well as ideas for future work.

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    fulltext
  • 47.
    Ahlin, Eddie
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Presentation och lagring av data från vibrationsmätning utförd i ett kallvalsverk2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The fourth industrial revolution means that the steel manufacturing industry are faced with great challenges, where less environmental impact combined with high competition sets high expectations for the manufacturing method of steel. To achieve improvements in manufacturing and raise competitiveness, many manufacturers choose to digitalize their businesses to a greater extent. As a step in the digitalization process, Sandvik SMT Strip has chosen to extend one of their existing control systems with a CMS-module and sensors for vibration measurement.

    This bachelor thesis intends to present a proof of concept for presenting and storing data collected through vibration measurement in a cold rolling mill at Sandvik SMT Strip. The thesis work will be part of a pilot project at Sandvik SMT Strip. The goal of the pilot project is to achieve a well implemented vibration measurement solution to be able to use more predictive maintenance instead of the proactive and reactive maintenance used today. If an adaptation can be achieved where predictive maintenance is used to a larger extent the prospects are to save resources and time.

    The method for this thesis work has been experimental work in which the desired results have been governing. The result of this thesis work is a solution proposal for storing and presenting the data of vibration measurement in both time and frequency domain. Some parts of the solution proposal have been started with the goal to achieve a proof of concept.

    The conclusion presented in this thesis work is that an implementation for storing and presenting collected data with the desired soft- and hardware is possible, but more time is needed to obtain a proof of concept.

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  • 48.
    Ahlund, Viktor
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energikartläggning av förskolan Smultronstället2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is an energy audit with recommended energy efficient solutions recommended made on a preschool in north Gävle. This preschool is administrated by Gavlefastigheter. In Sweden almost 40 % of Sweden’s energy supply goes to the housing and service sector. This means there is a lot of potential to save energy in this field. A good way to start saving energy in a building is to do an energy audit.This energy audit is made from blueprints of the building, real measurements, standard values, assumptions, and literature.The school has a calculated energy use of 1239 MWh per year; this is divided on ventilation, transmission losses and hot tap water. A calculation with energy efficient solutions makes a total of 612 MWh or 49, 4 % in saved energy. The energy efficient savings calculated are new windows, additional insulation and changed ventilation. To only change the ventilation made for an energy saving of 522 MWh which is 42, 1 % from the total energy use in the building. To change the ventilation to an FTX-system is the recommended change to be made.

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  • 49.
    Ahmad, Afaq
    et al.
    Department of Civil Engineering, University of Engineering and Technology, Taxila, Rawalpindi 46600, Pakistan.
    Bahrami, Alireza
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Alajarmeh, Omar
    Centre for Future Materials (CFM), School of Civil Engineering and Surveying, University of Southern Queensland, Toowoomba 4350, Australia.
    Chairman, Nida
    Department of Civil and Architectural Engineering, University of Westminster, London W1B 2HW, UK.
    Yaqub, Muhammad
    Department of Civil Engineering, University of Engineering and Technology, Taxila 47080, Pakistan.
    Investigation of Circular Hollow Concrete Columns Reinforced with GFRP Bars and Spirals2023In: Buildings, E-ISSN 2075-5309, Vol. 13, no 4, article id 1056Article in journal (Refereed)
    Abstract [en]

    Glass fiber-reinforced polymer (GFRP) reinforcements are useful alternatives to traditional steel bars in concrete structures, particularly in vertical structural elements such as columns, as they are less prone to corrosion, and impart increasing strength and endurance of buildings. There is limited research on the finite element analysis (FEA) of the structural behavior of hollow glass fiber-reinforced polymer reinforced concrete (GFRPRC) columns. The hollow portion can be used for the service duct and for reducing the self-weight of the members. Numerical analysis of the compressive response of circular hollow concrete columns reinforced with GFRP bars and spirals is performed in this study. This article aims to investigate the axial behavior of hollow GFRP concrete columns and compare it with that of solid steel reinforced concrete (RC) columns as well as hollow steel RC columns. The Abaqus software is used to construct finite element models. After calibration of modeling using an experimental test result as a control model, a parametric study is conducted. The columns with the same geometry, loading, and boundary conditions are analyzed in the parametric study. It is resulted that the hollow GFRP concrete columns provide a greater confinement effect than the solid steel RC columns. The average variation in the ultimate axial load-carrying capacities of the experimental results, from that of the FEA values, is noted to be only 3.87%, while the average difference in the corresponding deformations is 7.08%. Moreover, the hollow GFRP concrete columns possess greater axial load and deformation capacities compared with the solid steel RC columns.

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  • 50.
    AHMAD, FAHEEM
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    KAKKERLA, PRAMOD
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    FOCUSING OF UWB RADAR SIGNALS USING TIME REVERSAL2013Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    Focusing techniques and detection of targets is usually associated to defense and military use. However in recent past things have moved ahead. Now target detection using UWB radars is being done in many industries and corporations. Radarbolaget AB is one of them; one of their projects uses UWB radars to detect steel strips inside a furnace. This research solves a potential problem of detecting middle steel strip out of total three strip edges which can be seen by radar placed on the front. For better understanding of the reader, existing system and introductory UWB radar principles are discussed. As there can be many solutions to focusing of targets here (steel strip edge detection). Available focusing techniques have been discussed in detail along with the possible physical and simulation setups. Later in the document, detection methods have been proposed. UWB time reversed signal detection is a fairly new method and a very limited research has been done so far. PRBS sequence has been focused on in detection mechanism. Results section show that the pulse of the PRBS works better and produces more promising results rather than a repetitive signal. Time reversal methods for locating the target have been used to find the approximate location of the target. Manual distance calculations from target to the transmitter and receiver have been done. Comparison of actual distance from target to the transmitter is compared with simulation results. Different model simulation setups and their results have proved that using UWB Time reversed signals; a still or moving target can be detected with centimeter window precision.

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    Authors: Faheem Ahmad, Pramod Kakkerla, Focusing of UWB Radar Signals Using Time Reversal
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