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  • 1.
    Abad, Shayan
    et al.
    Department of Computer and Geo-Spatial Sciences, University of Gävle, 801 76 Gävle, Sweden.
    Gholamy, Hassan
    Department of Computer and Geo-Spatial Sciences, University of Gävle, 801 76 Gävle, Sweden.
    Aslani, Mohammad
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för datavetenskap och samhällsbyggnad, Datavetenskap.
    Classification of Malicious URLs Using Machine Learning2023Ingår i: Sensors, E-ISSN 1424-8220, Vol. 23, nr 18, artikel-id 7760Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Amid the rapid proliferation of thousands of new websites daily, distinguishing safe ones from potentially harmful ones has become an increasingly complex task. These websites often collect user data, and, without adequate cybersecurity measures such as the efficient detection and classification of malicious URLs, users’ sensitive information could be compromised. This study aims to develop models based on machine learning algorithms for the efficient identification and classification of malicious URLs, contributing to enhanced cybersecurity. Within this context, this study leverages support vector machines (SVMs), random forests (RFs), decision trees (DTs), and k-nearest neighbors (KNNs) in combination with Bayesian optimization to accurately classify URLs. To improve computational efficiency, instance selection methods are employed, including data reduction based on locality-sensitive hashing (DRLSH), border point extraction based on locality-sensitive hashing (BPLSH), and random selection. The results show the effectiveness of RFs in delivering high precision, recall, and F1 scores, with SVMs also providing competitive performance at the expense of increased training time. The results also emphasize the substantial impact of the instance selection method on the performance of these models, indicating its significance in the machine learning pipeline for malicious URL classification

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  • 2.
    Ahmadi, Fereshteh
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för socialt arbete och psykologi, Sociologi/Socialt arbete.
    Ahmadi, Babak
    Ethnic identity and the meaning of context: a study of second generation Iranians in Sweden2012Ingår i: The Iranian community in Sweden: multidisciplinary perspectives / [ed] Hassan Hosseini-Kaladjahi, Tumba: Mångkulturellt centrum , 2012, 1, s. 193-220Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 3. Akter, Ruzlin
    et al.
    Rathnayaka, Shashiprabha
    Ahmadi, Zahra
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    The effect of leadership and organisational culture on organisational innovation2023Ingår i: International Journal of Services Technology and Management, ISSN 1460-6720, E-ISSN 1741-525X, Vol. 28, nr 5/6, s. 360-388Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose

    The purpose of the study is to explore the impact of company leadership and organizational culture in the development of organizational innovation.

    Design/methodology/approach

    The qualitative approach is applied via 12 interviews from six different organizations, encompassing both service providers and product manufacturers, in the countries of Sweden and Sri Lanka.

    Findings

    Leadership and organizational culture together influence the development of innovation. The findings suggest that process- and job-oriented culture, as well as transactional leadership, have both positive and negative impacts in developing innovation. Result-oriented, employee-oriented, pragmatic culture and an open system, together with transformational leadership, are found to be more effective.

    Research limitations/implications

    This study was limited to six organizations, specific industries and national cultures. Researchers could explore in depth to identify which factors particularly lead to the failure or success of innovativeness in a particular industry, through comparing national cultures.

    Practical implications

    This study helps managers decide how to serve best within the organizational and national culture, while learning about the influential result of the culture and leadership on innovation. With the aid of this study, organizations will be able to identify factors that may help them to be innovative and competitive in the market.

    Originality

    This study highlights the importance of leadership and organizational cultures effect on an organization's innovation, as well as showing how it improves the companies ability to both meet consumer expectations and contribute to their national economy. 

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  • 4.
    Ameen, Arman
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Bahrami, Alireza
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    El Tayara, Khaled
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Energy Performance Evaluation of Historical Building2022Ingår i: Buildings, E-ISSN 2075-5309, Vol. 12, nr 10, artikel-id 1667Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Retrofitting measures in old buildings aimed at reducing energy usage have become important procedures meant to counteract the effects of climate change and greenhouse gas emissions. The aim of this study is to evaluate energy usage, thermal comfort, and CO2 emissions of an old building by changing parameters such as building orientation, shading systems, location, low energy film application, and alternative energy supply in the form of a geothermal heat pump. When evaluating the buildings in terms of geographical location with or without applying the low energy film, the results show that the city of Gävle in Sweden requires the most heating energy, 150.3 kWh/m2∙year (B0) compared to Jakarta (L0), which requires 23.8 kWh/m2∙year. When examining the thermal comfort, cases B4 and L4 demonstrate the best results in their respective categories (B0–B4 are cases without low energy film and L0–L4 are cases with applied low energy film). The results for the CO2 emissions levels for B0–B4 and L0–L4 indicate that B4 has the highest value, 400 kg CO2 eq/year higher than B0, and L1 has the lowest value, 731 kg CO2 eq/year lower than B0. The economic feasibility study illustrates that the installation of a geothermal heat pump with at least a coefficient of performance of 4.0 leads to a shorter payback period than solely applying LEF.

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  • 5.
    Ameen, Arman
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Bahrami, Alireza
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Elousa Ansa, Ibai
    Assessment of Thermal Comfort and Indoor Air Quality in Library Group Study Rooms2023Ingår i: Buildings, E-ISSN 2075-5309, Vol. 13, nr 5, artikel-id 1145Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Human performance and health are among the most relevant topics in the modern society, especially at young ages, when academic performance is indispensable. Thus, as humans spend most of their lifetime inside a building, thermal comfort and indoor air quality are an essential aspect of a room. The aim of the current study is to numerically evaluate the main thermal comfort parameters such as PMV and PPD as well as indoor air quality, i.e., CO2 concentration, in library group study rooms at the University of Gävle in Sweden. Rotroninc Measurement Solutions CL11 sensors were utilized for temperature measurements. Simulation models were created and validated based of building data as well as temperature measurements. Several simulations were conducted throughout a year, covering different periods. The results show that even though the ventilation system, with only temperature control, works as intended for maintaining the thermal comfort, the CO2 concentration rises above 1000 ppm when more than one student occupy the rooms, which is not recommended by different thermal comfort ruling institutions. Consequently, a modification to the ventilation system control is recommended, changing it from temperature control to CO2 and temperature control.

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  • 6.
    Ameen, Arman
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Mattsson, Magnus
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Boström, Hanna
    Lindelöw, Hanna
    Assessment of Thermal Comfort and Air Quality in Office Rooms of a Historic Building: A Case Study in Springtime in Continental Climate2023Ingår i: Buildings, E-ISSN 2075-5309, Vol. 13, nr 1, artikel-id 156Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the most important aspects of working in an office environment is ensuring that the space has optimal thermal comfort and an indoor environment. The aim of this research is to investigate the thermal comfort and indoor climate in three office rooms located at one of the campus buildings at the University of Gävle, Sweden. The evaluated period is in the month of April during springtime. During this period, parameters such as temperature, relative humidity, CO2, supply air flow rate, and room air velocities are measured on site. The results of the measurement show that the indoor temperature is on average lower in the rooms facing north, at 21–23.5 °C, compared to the rooms facing south, which reach high temperatures during sunny days, up to 26 °C. The results also show that the ventilation air supply rate is lower than the requirement for offices in two of the office rooms. The ACH rate is also low, at ≈ 1 h−1 for all the rooms, compared to the required levels of 2–4 h−1. The CO2 levels are within the recommended values; on average, the highest is in one of the south-facing rooms, with 768 ppm, and the maximum measured value is also in the same room, with 1273 ppm for a short period of time.

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  • 7.
    Amin, A.
    et al.
    Teleconnect GmbH, Dresden, Germany; University of Applied Sciences Dresden, Dresden, Germany.
    Bluschke, A.
    Teleconnect GmbH, Dresden, Germany.
    Emery, S.
    Innodul AG, Zürich, Switzerland.
    Krüger, F.
    Teleconnect GmbH, Dresden, Germany; University of Applied Sciences Dresden, Dresden, Germany.
    Matthews, M.
    Teleconnect GmbH, Dresden, Germany.
    Rietzsch, P.
    Teleconnect GmbH, Dresden, Germany.
    Steglich, R.
    Contec Steuerungstechnik and Automation GmbH, Ebbs, Austria.
    Multi-carrier transmission over si-pof2011Ingår i: POF 2011: 20th International Conference on Plastic Optical Fibers - Conference Proceeding, 2011, s. 81-86Konferensbidrag (Refereegranskat)
    Abstract [en]

    Multi-carrier modulation (MCM) is today’s method of choice for communication systems. This is also true for SI-POF. The basics of MCM and special characteristics for the optical transmission using SI-POF are explained within this paper. Current approaches for MCM over SI-POF are described: Teleconnect’s G.hn based solution for home networking and Innodul’s DMT-based Gigabit solution.

  • 8.
    Andersson, Daniel
    et al.
    Radarbolaget, Gävle.
    Wallin, Kjell
    Radarbolaget, Gävle.
    Javashvili, Otar
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Beckman, Claes
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    M-Sequence UWB Radar for Industrial Applications2010Ingår i: Program of GigaHertz Symposium 2010, March 9-10, at Lund University, 2010Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

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

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

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

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

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

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  • 9.
    Andersson, Harald
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Sundberg, Mikael
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap.
    Senkic, Dario
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för industriell ekonomi, industridesign och maskinteknik.
    Sandberg, Mats
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Kabanshi, Alan
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    FAST-AIR: Fast analytic systems for tracer-gas assessment in indoor research: Development and testing of CO2 tracer-gas system.2024Konferensbidrag (Refereegranskat)
    Abstract [en]

    The time constant of ventilation of rooms in buildings is between 15 minutes (in office spaces) to 2 hours (in residential buildings). Currently, most of the tracer gas system analyzers on the market have a minute-based time constant and depending on the channels a cycle of sampling and analysis may take up to 6 minutes, E.g., 6 channel system. Essentially, only mean values are recorded with most present tracer gas analyzers. This is a hindrance for detailed temporal analysis of conditions in the room and consequently is does not capture the resolution of the influence of the internal flow on air and contaminant distribution. The current paper presents work on the development and testing of a fast response CO2 tracer-gas system with a time constant of 1 second. In contrast to the present analyzers, not only the mean values but also the whole statistical distribution of variables can be recorded, and pulse responses can be analyzed. This makes the system viable for measurement and analysis of not only spatial but also temporal distribution of contaminants. For example, recirculating airflow in the room generated by flooding of ventilation air is possible to be measured and thus making it easy to extend the analyses of the process of ventilation far beyond the possibilities with current systems.

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  • 10. Andersson, Jenny
    Hög musik från bilar i Falu kommun: Kartläggning och åtgärdsförslag2020Rapport (Övrigt vetenskapligt)
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  • 11.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Ameen, Arman
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Halvarsson, Mattias
    Aho, Mikael
    Potential Electricity Production of Roof-Mounted Solar PV Systems in a Row House Area in Sweden2023Ingår i: Sustainable Technology for Society 5.0: Case Studies, Examples, and Advanced Research Findings / [ed] Tilottama Singh, Richa Goel, Jan Alexa Sotto, CRC Press, 2023, s. 167-182Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Sweden's energy policy goal is to have completely renewable electricity production by the year 2040; thus, alternatives such as wind and solar energies are being investigated for electricity supply, where mainly solar energy has the potential for small and medium-sized systems for houses of private individuals and companies. As a part of this development, the tenant-owner's association, Stenbär, in the city of Gävle in Sweden has considered installing solar PV systems, which has become the basis for this research. The aim of this chapter is to investigate the potential areas for a solar cell plant, and how much electricity this could produce per year. The simulations are performed by using the computer software IDA ICE 5.0 beta. It is demonstrated that there is a good potential to produce a large amount of solar energy in the area. As the system produces a surplus during the summer half of the year, there is also the possibility of selling the electricity.

  • 12.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Awn, Rim Fares
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Corona, Jaqueline
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Eriksson, Bengt
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    How Aware and Active is the Swedish Building and Real Estate Sector in Climate-Smart Concrete?2022Ingår i: International Journal of Engineering Trends and Technology, E-ISSN 2231-5381, Vol. 70, nr 1, s. 126-138Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carbon dioxide has long proven to be one of the greenhouse gases that affects our planet's climate and environment. With the forthcoming European Union goals and Sweden's own net-zero goal, it is required that the building and real estate sector works with climate-smart materials to construct future buildings. The net-zero goal by 2045 requires a common effort from all companies to find innovative solutions in order to reduce carbon dioxide emissions sharply. This study investigates how aware and active the building and real estate sector is in climate-smart concrete (CSC) through a survey and comparison of environmental product declarations (EPDs). Climate-smart is a term for concrete that contains a lower percentage of Portland cement clinker than traditional concrete. This research aims to examine how far the development has taken place and to evaluate how the market has adopted the newly available products. It is als assessed which alternative additive materials are the most common as well as advantages and disadvantages of the CSC. A questionnaire is created, and the survey is sent out to companies. A comparison is made between three different EPDs of the CSC and two references for concrete with the ordinary Portland cement clinker. Reference concrete 1 is a standard value, and reference concrete 2 is an EPD value. A reference building is used to calculate the volume and weight of its utilized concrete. The three types of the CSC are compared with the reference concrete 1, and the results show a carbon dioxide reduction of 29.3%. However, the comparison of these three types of the CSC with the reference concrete 2 demonstrates a carbon dioxide reduction of 2.8%. In addition, it is concluded that the future will require the building and real estate sector to invest time and training to work with the CSC further.

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  • 13.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Azizian, Dawod
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Assessment of glulam and reinforced concrete beams in multi-storey building2022Ingår i: Civil and Environmental Engineering, ISSN 1336-5835, Vol. 18, nr 1, s. 66-75Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study assesses glulam and reinforced concrete (RC) beams in a multi-storey building in Gävle in Sweden. StruSoft FEM-Design software is used to conduct the current study. First, the building having the RC beams is modelled, analysed, and designed. Utilisation ratio, stress, weight, reaction force, stability, and deflection of the building are examined. It is concluded that the building can function well with RC beams. Then, the RC beams are replaced with glulam beams and the building is again analysed. It is revealed that larger cross-sections are needed for the replaced glulam beams in most of the spans compared with the RC beams in order for them to have acceptable results from the utilisation ratio viewpoint. However, for large spans of 8 m, a timber column is used in the mid-span for all the storeys as a strengthening alternative so that a shorter span for these glulam beams can be adopted which leads to acceptable results. Stresses of the RC and glulam beams are also evaluated. The building having the glulam beams is 23.79 % lighter than the building having the RC beams. The maximum reaction force of the building having the glulam beams is obtained 24.27 % lower than the building having the RC beams. Stability and deflection of the building in both cases are discussed as well.

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  • 14.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Blomberg, Emil
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Boqvist, Simon
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Lauridsen, Markus
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Eriksson, Bengt
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Experimental Investigation of Ultimate Shear Force Capacity of Glulam Reinforced with Glued-in Threaded Rods2023Ingår i: The Open Construction & Building Technology Journal, ISSN 1874-8368, Vol. 17, s. 1-12Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Abstract:

    Background:

    Glued-in threaded (GIT) rods have been considered an effective timber connection method having several advantages, such as high load-carrying capacity, great stiffness, and good fire resistance. This type of connection has widely been utilized in newly built modern timber structures and for reinforcing the existing ones.

    Objective:

    The purpose of this experimental research is to investigate how the ultimate shear force capacity (USFC) of glulam is affected if it is reinforced with GIT rods and to study the interaction between the glulam and GIT rods. The results of this research can help researchers and engineers to select a suitable method of reinforcing the glulam with GIT rods at a superior inclination angle (IA) to the fiber direction in order to achieve higher USFCs.

    Methods and Experimental Tests:

    A total of forty glulam samples were tested for failure. The experimental tests consisted of five different series of samples with eight samples in each series. Sample series 1 were unreinforced glulam. Sample series 2 and 4 were glulam reinforced with the GIT rods at two different IAs of 45° and 90° to the fiber direction, respectively. Sample series 3 and 5 were glulam reinforced in the same way as sample series 2 and 4, but they were split in the middle. The samples were tested for failure using a standard testing machine. The machine was connected to a computer that recorded all the values obtained from the tests.

    Results:

    The results of the study were obtained as force-displacement graphs. The stiffness of the samples and interaction between the glulam and GIT rods were also calculated. The results achieved from the experimental tests of different series were compared and discussed.

    Conclusion:

    The experimental tests resulted in a 12.5% increase in the average USFC of sample series 2. However, the average USFC of sample series 4 was not enhanced significantly. The interaction between the glulam and GIT rods was obtained as 31.8% for the samples with reinforcing at the IA of 45° to the fiber direction and 3.8% for the samples with reinforcing at the IA of 90° to the fiber direction. Reinforcing the glulam with the GIT rods demonstrated the potential of enhancing its USFC. However, reinforcing the glulam with the GIT rods at the IA of 45° to the fiber direction was found to be superior to reinforcing the glulam with the GIT rods at the IA of 90° to the fiber direction.

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  • 15.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Deniz, Suleyman
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Moalin, Hassan
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Vertical Extension of a Multi-Storey Reinforced Concrete Building2022Ingår i: International Journal of Applied Mechanics and Engineering, ISSN 1425-1655, Vol. 27, nr 1, s. 1-20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The global population is increasing annually; thus, there is a need for more housing and buildings worldwide. As cities grow outward and buildable lands become scarce, it is necessary to increase the height of existing buildings in cities, especially where the height of the buildings is low. For crowded cities, the storey extension is an increasingly popular measure that can meet market demand for centrally located houses. This paper examines the possibility of the vertical extension of an existing (reference) reinforced concrete building in Gävle in Sweden. The StruSoft FEM-Design program is employed to carry out the research. The building is firstly modelled, analysed and designed completely. Thereafter, a storey extension is conducted vertically. The stresses and utilisation ratios of the load-bearing elements of the reference and extended buildings are assessed. It is found that some of the load-bearing elements of the building after the extension need strengthening. Different practical strengthening solutions are proposed. It is concluded that the building can successfully withstand the vertical extension after applying these proposed solutions. The maximum vertical reaction forces of the reference and extended buildings are obtained and compared. A comparison of the deflections of the buildings is made. The structural stability of the buildings is evaluated as well. 

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  • 16.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Edås, Martin
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Magnenat, Kevin
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Norén, Johan
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    The behavior of cross-laminated timber and reinforced concrete floors in a multi-story building2022Ingår i: International Journal of Advanced and Applied Sciences, ISSN 2313-626X, Vol. 9, nr 6, s. 43-50Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The behavior of cross-laminated timber (CLT) and reinforced concrete (RC) floors in a multi-story building is investigated in this article. The load-bearing capacity, fire resistance, and sound insulation characteristics of the floors are the main focus of this research. In order to achieve this goal, a four-story building having RC floors is modeled, analyzed, and designed using the StruSoft FEM-Design software (FEM) following the Eurocodes and Swedish national annex. The building is considered to be in the city of Gävle in Sweden. Then, the RC floors of the building are replaced with the CLT floors, and the same process is done utilizing FEM. The utilization ratios (the ratios of the applied loads to the load-bearing capacities), vertical deflections, weights of the RC and CLT floors, and reaction forces of the buildings are evaluated and compared. The results show that the RC floors meet the deflection requirements well which contribute to the focus on their utilization ratios. The designed RC floors are acceptable from the vertical deflection and utilization ratio perspectives. However, the CLT floors cannot meet the vertical deflection requirements, and thus, need strengthening. The CLT floors are strengthened with supporting timber beams and columns which result in acceptable vertical deflections and utilization ratios. Fire resistance and sound insulation conditions of the RC and CLT floors are assessed by calculations based on the requirements of the Swedish National Board of Housing, Building, and Planning regulations (BBR) as well. The RC floors have the ability to be soundproof and have no difficulties in meeting the fire resistance requirements R60 of BBR. A cross-section is proposed for the CLT floors which can meet the fire resistance requirement R60 and sound insulation requirement C of BBR. The maximum reaction forces of the buildings and total weights of the floors are larger in the case of RC than CLT.

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  • 17.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Hornborg, Angelika
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Persson, Sofia
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Norén, Johan
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Bengtsson Asplin, Björn
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Evaluation of Untreated and Surface-Treated Wooden Facades of Buildings in Sweden2023Ingår i: Coatings, ISSN 2079-6412, Vol. 13, nr 4, artikel-id 746Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this research, untreated and surface-treated wooden facades of buildings are investigated and compared with regard to durability, environmental impact, and cost using the document and literature studies supplemented with quantitative data. The investigation is based on the influence on the wood by external factors, either in its natural form or with a protective layer of a surface treatment. It is resulted from the study that from a durability viewpoint, it is not always advantageous to paint a wooden facade. Yakisugi, a thermal modification for wooden facades that involves burning the wood to create a protective surface layer, has shown better properties, which, in combination with a lower need for maintenance, can be considered the leading treatment for facades. From an environmental perspective, Yakisugi, like untreated wood, has demonstrated advantages compared with conventional paints. Paints often come with maintenance requirements that should be carried out correctly to avoid extensive costs. Cost is an important factor that can be decisive when users choose a surface treatment. What determines the cost is the relationship between durability and maintenance intervals. The need for the maintenance of paints leads to large financial costs during the working life of a wooden facade, which differs from Yakisugi or an untreated wooden facade that can be considered maintenance-free. In order to meet the growing environmental demands from a national level to a global scale, unconventional surface treatments for wooden facades should be promoted in the future.

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  • 18.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Jakobsson, Jonas
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Söderroos, Tobias
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap.
    Factors Influencing Choice of Wooden Frames for Construction of Multi-Story Buildings in Sweden2023Ingår i: Buildings, E-ISSN 2075-5309, Vol. 13, nr 1, artikel-id 217Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Construction of buildings with wooden frames higher than two stories has been permitted in Sweden since 1994. As construction of multi-story buildings with wooden frames is relatively new, people in the construction industry are more likely to construct these buildings with concrete frames. The current research evaluates the factors influencing the choice of wooden frames for construction of multi-story buildings in Sweden. The purpose of this study is to explain which advantages and disadvantages construction companies in Sweden consider with wooden construction and to highlight the factors for why multi-story buildings are built with wood to a lesser extent than with other materials. The main goal is to investigate what factors or assumptions construction companies base their decisions on, and whether experience and competence in wooden frames for construction of multi-story buildings are considered in short supply in Sweden today. The chosen method for this research is a descriptive survey study with a qualitative and quantitative approach. The survey is based on respondents from five leading building companies in Sweden with regard to the companies’ revenue. The respondents had either previous experience in constructing multistory buildings with wooden frames, experienced respondents (ERs), or no experience, unexperienced respondents (UERs). 63% of the respondents were ERs, while 37% of them were UERs. It is resulted that the respondents think there is a lack of competence and experience in wooden frames for construction of multi-story buildings in Sweden. Factors that have the greatest impact on decisions to construct with wooden frames are positive environmental and climatic aspects as well as production advantages. Factors that are considered as major obstacles to construct with wooden frames are cost, acoustics, and moisture problems.

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  • 19.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Lindqvist, Moa
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Lindqvist Berglund, Lisa
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Eriksson, Bengt
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Important Criteria for Swedish Construction Companies to Choose Environmentally Friendly Concrete2023Ingår i: Civil Engineering Journal, ISSN 2676-6957, Vol. 9, nr 1, s. 197-207Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Today, ordinary Portland cement-based concrete is one of the most important building materials and is widely used in new building construction, which is an environmental problem, as cement production accounts for 5%-8% of the world's carbon dioxide emissions. Thus, the need for using more environmentally friendly concrete (EFC) is growing. However, it is stated that Swedish construction companies are reluctant to change and adopt new construction methods and materials. This research aims to map the important criteria for Swedish construction companies to choose EFC for use in their projects. The study is carried out based on a literature study and a questionnaire survey. The questionnaire is designed considering the significant criteria of EFC derived from the literature study. The respondents from the Swedish construction companies were asked to rate these various criteria. The collected results are presented with bar graphs. The results show that the highest valued criterion by the respondents for the use of EFC in the projects is its long-term properties, while the lowest one is the possibility of introducing a specific ceiling for greenhouse gas emissions by the companies.

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  • 20.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Oliver, Nexén
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Jonsson, Jonas
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Comparing performance of cross-laminated timber and reinforced concrete walls2021Ingår i: International Journal of Applied Mechanics and Engineering, ISSN 1425-1655, Vol. 26, nr 3, s. 28-43Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this research is to specify the differences between the performance of cross-laminated timber (CLT) and reinforced concrete (RC) walls. The study is done by using the finite element structural analysis and design software, StruSoft FEM-Design, in order to model, analyse and design a reference building located in the city of Gävle in Sweden. The building is firstly modelled, analysed and designed using RC walls and then the RC walls are replaced with CLT walls. In both buildings, other load-bearing elements such as slabs, beams and columns are made of RC while the roof beams are made of glulam. It is found that employing RC has advantages, especially regarding thickness. The results show that the CLT walls require larger dimensions than their RC counterparts. Meanwhile, it is demonstrated that the slabs, beams and columns made of RC in the building having the CLT walls require more reinforcement or larger thickness than the case of walls made of RC. Moreover, the total weight of the building having the CLT walls is 74% of the building having the RC walls. The lower weight of the building having the CLT walls has great advantages such as having lighter foundation and being cost-effective and also beneficial for the environment.

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  • 21.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Olsson, Markus
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Svensson, Karl
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Carbon Dioxide Emissions from Various Structural Frame Materials of Single-Family Houses in Nordic Countries2022Ingår i: International Journal of Innovative Research and Scientific Studies, ISSN 2617-6548, Vol. 5, nr 2, s. 112-120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Since the choice of material for the construction of single-family houses has a major impact on the buildings' total carbon dioxide emissions, this study examines the carbon dioxide emissions from various structural frame (frame) materials used for single-family houses in the Nordic countries. The analysed frame materials are wood, concrete, and steel as they are the most frequently chosen for single-family houses in these countries. To map the carbon dioxide emissions from the frame materials, a literature review of existing life cycle analyses of the materials is conducted. To present the results, a typical wall is employed for each material; the width and height of the walls are 1 m, while the depth varies for the different materials. The walls are designed to illustrate the results, which are reported in kg CO2/m3. Moreover, the study includes interviews with housing manufacturers to get the building industry's views on the choice of frame material with regard to carbon dioxide emissions. The results show that there are major differences in the carbon dioxide emissions from the three frame materials. The wooden, steel, and concrete frames emit 96 kg CO2/m3, 209 kg CO2/m3, and 602 kg CO2/m3, respectively. The results confirm that the wooden frame has the lowest carbon dioxide emissions, which makes it the most environmentally friendly frame in the Nordic countries when compared with the steel and concrete frames.

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  • 22.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Vall, Andreas
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Khalaf, Asaad
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Comparison of cross-laminated timber and reinforced concrete floors with regard to load-bearing properties2021Ingår i: Civil engineering and architecture, ISSN 2332-1091, E-ISSN 2332-1121, Vol. 9, nr 5, s. 1395-1408Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Floors of a building with the relatively new and environmentally sustainable structural material as cross-laminated timber (CLT) and traditional reinforced concrete (RC) are compared in this paper with regard to their load-bearing properties. StruSoft FEM-Design software is utilised to model, analyse and design an existing building using the CLT and RC floors. The building has three stories with a penthouse on the top floor. Modelling, analysis and design of the building can be summarised into five main steps. In step 1, the building with the RC floors is modelled, analysed and designed according to the geometries and specifications of the building. The RC floors of the building are then changed to the CLT floors with the similar thickness and the function of the building is checked for tensile and compressive stresses, utilisation ratio and deflection in step 2. Step 3 involves checking what reinforcing is required for the CLT floors to be approved with about the same thickness as the RC floors. In step 4, it is controlled whether a larger thickness of the CLT floors without reinforcing can withstand the identical conditions of the RC floors. From the obtained results, effects of thickness of the CLT floors and span width are examined. The structural stability of the building with the CLT and RC floors is controlled in step 5. Further, the CLT and RC floors of the building are compared in terms of their stresses, utilisation ratios and weights. The results of this paper demonstrate advantages of using the CLT floors. The CLT floors show good strength properties compared with their low weights. It is uncovered that the building with both of the CLT and RC floors is stable. Obtained results of the building with the CLT and RC floors from the StruSoft FEM-Design software are compared with those from calculations based on Eurocode 2 and Eurocode 5, which reveal good agreements with each other regarding their accuracy.

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  • 23.
    Bahrami, Alireza
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Ågren, Felicia
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Kollberg, Kim
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för byggnadsteknik, energisystem och miljövetenskap, Energisystem och byggnadsteknik.
    Strengthening solutions for deep reinforced concrete beam with cutout opening2021Ingår i: Buildings, E-ISSN 2075-5309, Vol. 11, nr 8, artikel-id 370Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Since reinforced concrete (RC) buildings have long service life, cutout openings are generally needed in their load‐bearing walls as a sustainable solution in order to meet new requirements of their users. However, the cutout openings decrease the load‐bearing capacity of the walls, which may result in the failure of the buildings. In this paper, we investigate the possibility of making a door opening in a load‐bearing RC wall of an existing building in Gävle in Sweden. The wall studied in the current paper rests on two individual supports at its two ends; thus, it is considered as a deep beam. However, it is called an examined wall (EW) here. The StruSoft FEM‐Design software is used in this study to model, analyze, and design the building based on the Eurocodes and Swedish national annex. The potential need for the EW to be strengthened when the cutout opening is made is also evaluated. It is concluded that strengthening the EW with cutout opening is needed. Different strengthening solutions are proposed for the EW. Moreover, the situation of the EW with the solutions is assessed with regard to the utilization ratio, deflection, and weight. Consequently, it is demonstrated that the proposed strengthening solutions function well for the EW.

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  • 24.
    Boman, Eva
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för socialt arbete och psykologi, Psykologi.
    Ballgren, Peter
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för socialt arbete och psykologi, Psykologi.
    Svedberg, Pia
    Karolinska Inst, CNS, Stockholm, Sweden.
    Is health related quality of life among school children associated with level of semantic memory?2010Ingår i: Quality of Life Research, ISSN 0962-9343, E-ISSN 1573-2649, Vol. 19, s. 107-107, artikel-id 194/1380Artikel i tidskrift (Övrigt vetenskapligt)
  • 25.
    Candell, Agneta
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för hälso- och vårdvetenskap, Vårdvetenskap.
    Engström, Maria
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för hälso- och vårdvetenskap, Vårdvetenskap. Uppsala universitet.
    Dental hygienists’ work environment: motivating, facilitating, but also trying2010Ingår i: International Journal of Dental Hygiene, ISSN 1601-5029, E-ISSN 1601-5037, Vol. 8, nr 3, s. 204-212Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of the present study was to describe dental hygienists' experiences of their physical and psychosocial work environment. The study was descriptive in design and used a qualitative approach. Eleven dental hygienists participated in the study and data were collected during spring 2008 using semi-structured interviews. The material was analysed using qualitative content analysis. The results showed that the dental hygienists experienced their work environment as motivating and facilitating, but at the same time as trying. The three categories revealed a theme: Being controlled in a modern environment characterized by good relationships. Motivating factors were the good relationship with co-workers, managers and patients, seeing the results of your work, having your own responsibility and making your own decisions. The new, pleasant and modern clinics, good cooperation between co-workers and varying duties were described as facilitating factors. The trying factors, as described by the dental hygienists, were above all being controlled by time limits or by some elements of the work, such as teamwork. The dental hygienists also felt stress because appointments were too-short. To conclude, the participants described their work environment as trying in several ways, despite the modern clinics and good relationships.

  • 26.
    Candell, Agneta
    et al.
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för hälso- och vårdvetenskap, Vårdvetenskap.
    Engström, Maria
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för hälso- och vårdvetenskap, Vårdvetenskap.
    Dental hygienists' work environment: motivating, facilitating, but also trying2010Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 27.
    Chang, Keke
    et al.
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Chen, Ruipeng
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Wang, Shun
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Li, Jianwei
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Hu, Xinran
    School of Human Nutrition and Dietetics, McGill University, Canada..
    Liang, Hao
    Cao, Baiqiong
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Sun, Xiaohui
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Ma, Liuzheng
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Zhu, Juanhua
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China.
    Jiang, Min
    College of life sciences, Henan Agricultural University, Zhengzhou, China.
    Hu, Jiandong
    Department of Electrical Engineering, Henan Agricultural University, Zhengzhou, China; State key laboratory of wheat and maize crop science, Zhengzhou, China.
    Considerations on Circuit Design and Data Acquisition of a Portable Surface Plasmon Resonance Biosensing System2015Ingår i: Sensors, E-ISSN 1424-8220, Vol. 15, nr 8, s. 20511-20523Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to develop a circuit for an inexpensive portable biosensing system based on surface plasmon resonance spectroscopy. This portable biosensing system designed for field use is characterized by a special structure which consists of a microfluidic cell incorporating a right angle prism functionalized with a biomolecular identification membrane, a laser line generator and a data acquisition circuit board. The data structure, data memory capacity and a line charge-coupled device (CCD) array with a driving circuit for collecting the photoelectric signals are intensively focused on and the high performance analog-to-digital (A/D) converter is comprehensively evaluated. The interface circuit and the photoelectric signal amplifier circuit are first studied to obtain the weak signals from the line CCD array in this experiment. Quantitative measurements for validating the sensitivity of the biosensing system were implemented using ethanol solutions of various concentrations indicated by volume fractions of 5%, 8%, 15%, 20%, 25%, and 30%, respectively, without a biomembrane immobilized on the surface of the SPR sensor. The experiments demonstrated that it is possible to detect a change in the refractive index of an ethanol solution with a sensitivity of 4.99838 × 10(5) ΔRU/RI in terms of the changes in delta response unit with refractive index using this SPR biosensing system, whereby the theoretical limit of detection of 3.3537 × 10(-5) refractive index unit (RIU) and a high linearity at the correlation coefficient of 0.98065. The results obtained from a series of tests confirmed the practicality of this cost-effective portable SPR biosensing system.

  • 28.
    Chowdhury, Ehsanul
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Fjellström, Daniella
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Mancuso, Giancarlo
    Addo, Richard
    Building Sports Brands and Fan Relationships During a Global Pandemic2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study aims to investigate the measures taken by hockey clubs, using SM, to build their brand and fan relationship during the COVID-19 pandemic in Sweden. To this end, the study looks at a variety of activities and commitments connected with SM, as well as taking into consideration the perspectives of both the hockey clubs and their fans.

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  • 29. Dahal, Robi
    et al.
    Mercan, Demet
    Lukas, Vojtech
    Telecommunications Engineering, Czech Technical University in Prague.
    Marek, Neruda
    Telecommunications Engineering, Czech Technical University in Prague.
    Textile Antenna for 50 ohm Applications2012Ingår i: Advances in Electrical and Electronic Engineering, ISSN 1336-1376, E-ISSN 1804-3119, Vol. 10, nr 4, s. 229-234Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The new generation of textile materials have the capability to conduct electricity and at the same time be wearable. There are much more applications involved if an antenna is made from parts that are totally wearable. This new property of conductivity in textile materials is used to implement the wireless functions to clothing. In general, the antennas are made of highly conductive metal with is a solid structure, which results in stable output. The challenge with textile antenna is output stability which is given by pure textile material of the radiating element, dielectric material and also ground, which can be can be folded and twisted. The paper presents the design and fabricated output results of the textile antenna which is used for the 50 ohm system (as GPS or WLAN) at 2,45 GHz.

  • 30.
    Dong, X.
    et al.
    Zhongyuan Univ Technol China, Zhengzhou , Peoples R China.
    Liu, Z.
    Zhongyuan Univ Technol China, Zhengzhou , Peoples R China.
    Yang, Y.
    Zhongyuan Univ Technol China, Zhengzhou , Peoples R China.
    Zhou, You
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Study on household metering and temperature control in central air-conditioning2010Ingår i: Proceedings of the 2010 5th IEEE Conference on Industrial Electronics and Applications, ICIEA 2010: Vol. 2, 2010, s. 931-935Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper studies the Frequency Temperature Control mechanism and cold (heat) metering algorithm about central air-conditioning terminal installations. The temperature control and household metering management system for central air-conditioning terminal machine are developed. The system hardware, software design programs and key technologies are expatiated. The terminal machine is integrated with PIC microcontroller, user data acquisition, transmission and control. Delphi language is used in the accounting management system of the host computer. The results show that, the system is no need of new wire, the high performance-price ratio, easy assembly, stable operation and reasonable charge. It is of great significance to adopt the heat and cold metering for the energy conservation, environmental protection and property management. At the same time, it provides the property management with a new technology and channels for the modern intelligent building. © 2010 IEEE.

  • 31. Dong, X.
    et al.
    Zhou, You
    Yang, Y.
    Ma, S.
    The design of wireless automatic meter reading system based on SOPC2010Ingår i: Proceedings - 2010 WASE International Conference on Information Engineering, ICIE 2010, Beidaihe, Hebei, 2010, Vol. 3, s. 11-14Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    According to the actual needs of the modern intelligent building,this paper introduces a intelligent meter reading system based on Nios II,which used the field programmable gate array FPGA EP2C35 and wireless transceiver chip nRF905 and then finished the design of the automatic meter reading system of the building.At the same time, it put forward the hardware structure of the system and software design process, customized the soft core processor and different peripheral interface controllers,established RS232 communication protocol,and at last implemented many functions of the electricity meter including real time collection,processing,data storage,wireless transmission and upper computer communication. It provides a new solution for the intelligent management of amodern buildings. © 2010 IEEE.

  • 32. Edström, Andreas
    et al.
    Nylander, Beatrice
    Molin, Jonas
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Ahmadi, Zahra
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Sörqvist, Patrik
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi.
    Where service recovery meets its paradox: Implications for avoiding overcompensation2022Ingår i: Journal of service theory and practice, ISSN 2055-6225, E-ISSN 2055-6233, Vol. 32, nr 7, s. 1-13Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose

    The service recovery paradox (SRP) is the phenomenon that happens when customer satisfaction level post-service failure and recovery surpasses the customer satisfaction level achieved at error-free service. The aim of this study was to identify how large the size of compensation has to be at recovery for customer satisfaction to surpass that of error-free service (i.e. to identify a threshold value for SRP). The purpose of this is to inform managers how to restore customer satisfaction yet avoid overcompensation.

    Design/methodology/approach

    The paper covers two studies. Study 1 used the novel approach of asking participants who had experienced a service failure in the hotel industry what amount of money (recovery) would make them more satisfied than in the case of error-free service. Study 2 then tested the compensation levels expressed by Study 1 participants to be sufficient for the service recovery paradox to occur.

    Findings

    Study 1 indicated that the threshold for the SRP was (on average) around 1,204 SEK, or just over 80% of the original room reservation price of 1,500 SEK (approx. $180). Study 2 found that (on average) the customer satisfaction of participants who received 1,204 SEK in compensation for service failure marked the point where it surpassed that of error-free service. Participants who received 633 SEK were less satisfied; participants who received 1,774 SEK were more satisfied.

    Research limitations/implications

    The findings are context-specific. Future research should test the findings' generalizability.

    Practical implications

    The approach used in this paper could provide managers with a tool to guide their service recovery efforts. The findings could help hotel managers to make strategic decisions to restore customer satisfaction yet avoid overcompensation, given a legitimate service failure in which the organization is at fault.

    Originality/value

    Numerous previous studies have investigated the occurrence or absence of the SRP at predetermined compensation levels. This paper used a novel approach to find a quantitative threshold at which the magnitude of the recovery effort makes customer satisfaction surpass that of error-free service

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  • 33.
    Ferrer Coll, Javier
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik. School of Information and Communication Technology, KTH Royal Institute of Technology, Kista, Sweden.
    Choquehuanca, Juan José
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Chilo, José
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Stenumgaard, Peter
    Swedish Defence Research Agency, P.O. Box 1165, SE-58111, Sweden.
    Statistical Characterization of the Electromagnetic Environment in a Hospital2010Ingår i: 2010 Asia-Pacific Symposium on Electromagnetic Compatibility, APEMC 2010, 2010, s. 293-296, artikel-id 5475847Konferensbidrag (Refereegranskat)
    Abstract [en]

    Thanks to advances in digital technology many hospitals are becoming populated with wireless medical applications to control life critical functions. Electromagnetic interference can cause severe performance degradations on these wireless applications. Several accidents have been reported which calls for a more thorough characterization of these interferences in areas where critical wireless applications are used. In this paper the results of electromagnetic interference measurements performed in a hospital are presented. The amplitude probability distribution (APD) and the inter arrival pulse probability distribution (PSD) are used to characterize these environments. In addition, Middleton parameters can be calculated from the measured data. This study is considered to be a first effort to characterize the 20 MHz -2500 MHz band in hospitals.

  • 34.
    Ferrer Coll, Javier
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik. KTH.
    Dolz Martin de Ojeda, Jose
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Stenumgaard, Peter
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik. FOI.
    Marzal Romeu, Silvia
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Chilo, José
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Industrial Indoor Environment Characterization: Propagation Models2011Ingår i: Proceedings of EMC Europe 2011 York - 10th International Symposium on Electromagnetic Compatibility, 2011, s. 245-249Konferensbidrag (Refereegranskat)
    Abstract [en]

    Results of three years' field measurements on radio propagation in industrial environments have been analyzed using four propagation models: the Saleh-Valenzuela model, the twocluster model, the indoor power delay profile model, and our more recent adjusted model. In this study, we used the results of measurements performed at a steel mill, a paper mill, and in a laboratory environment for three frequency bands (183-683 MHz, 1640-2140 MHz, and 2200-2700 MHz) and for line-of-sight and non-line-of-sight cases.

  • 35.
    Fjellström, Daniella
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Chowdhury, Ehsanul
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Ahmed, Sharif
    Islam, Md Tawhidul
    Influence of supply chain factors on reshoring decisions – A structured literature review2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    Aim: The purpose of this study is to explore how supply chain factors that influence decisions on reshoring have been discussed in previous research. 

    Methodology: A structured literature review is used to analyze 139 peer-reviewed articles containing reliable and effective arguments and discussion related to the aim of the study, retrieved from the online research databases of EBSCOhost, Science Direct, Emerald Insight and Springer. 

    Findings: The study identifies four supply chain factors that influence reshoring decisions, namely: supply chain resources, supply chain reconfiguration, the customer-supplier relationship, and supply chain proximity. 

    Implications of the study: This study provides a novel starting point from which future researchers can initiate empirical studies to evaluate the influence of the identified supply chain factors on reshoring decisions. The findings can, in addition, help practitioners and managers to develop knowledge of the influence of supply chain factors when making reshoring decisions. 

    Originality – This structured review extends our knowledge on the link between supply chain factors and reshoring, by drawing attention to how the factors of supply chain resources, supply chain reconfiguration, the customer-supplier relationship, and supply chain proximity influence reshoring decisions.

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  • 36.
    Fjellström, Daniella
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Chowdhury, Ehsanul
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Ahmed, Sohail
    Batkhuu, Bolortuya
    Implications for multinational enterprises from emerging market subsidiaries reverse knowledge transfer2023Ingår i: Central European Management Journal, ISSN 2336-2693, Vol. 31, nr 3, s. 326-343Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The study aims to understand the role of drivers, underlying challenges and, consequently, the implications of the reverse knowledge transfer (RKT) process for multinational enterprises (MNEs).

    Method: A dyadic qualitative research design was used with a cross-country design covering perspectives from both the parent companies (PCs) and subsidiaries from the United States, Denmark, Pakistan, India, and Bangladesh. In-depth interviews were conducted with managers in multiple sectors such as information technology, telecommunications, project management, and engineering.

    Findings: The study reveals the constraints and drivers of the RKT process, and furthermore elaborates on the implications for MNEs. RKT can lead to the development of new processes, subsidiary independence, and intra-organizational knowledge transfer. Besides, it can entail challenges such as position insecurity for subsidiaries and a blurring of the MNE market vision. The findings demonstrate several implications for the MNEs. 

    Implications: The study highlights the direct implications of RKT for the multinational enterprises. The findings serve as a practical guide for global managers seeking to improve their competitive edge.

    Originality: The study presents a framework of the RKT process from emerging market (EM) subsidiaries to PCs, that demonstrates the role of drivers, underlying challenges, and implications of the RKT process for the MNEs.

    Paper type: Research paper

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  • 37.
    Fjellström, Daniella
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Chowdhury, Ehsanul
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Osarenkhoe, Aihie
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Hartung, Kristina
    Hämäläinen, Emilia
    Enablers of international product positioning strategy – A Swedish SME’s case2022Ingår i: International Conference Proceedings: ICISET-22, ICBEN-22, LLESS-22 & IEMEL-22, 2022, Vol. 1, s. 111-112, artikel-id H112250Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study aims to identify the main factors that SMEs need to consider when positioning a premium priced product in the international market. In addition, this study aims to acquire in-depth knowledge regarding the market conditions in Germany. This study follows a qualitative research method, where a Swedish SME Damasteel acts as the case company of the research. In addition to the case company, four of their German distributors were interviewed using semi-structured interviews. The data were processed and presented by dividing the findings into six different categories. The empirical findings suggest that the German kitchen knife market is rather competitive, however, there is still potential for further growth and demand has been growing during the past few years. Personalisation of the products is considered one of the current trends. High quality of a product is often linked with high price, therefore, the main factors justifying premium price are the brand name, origin of the product, and customisation. This study contributes to the existing literature by adding new knowledge regarding product positioning and pricing strategies in the German market from the perspective of a Swedish SME. This study highlights the importance of premium price when positioning a high-quality product, therefore, it suggests that a premium product cannot be targeted to a mass audience. Practical recommendations offer insight to the case company Damasteel of the local market conditions in Germany, by providing an overview of the competition and customers in this segment. The focus of this study was on a niche market without offering any detailed information of the different factors influencing the market itself. Future research could supply an insight into how to better target the final customers of a specific market, and how to market a premium priced product for them. In addition, the pricing methods of the new product planned to be launched by the case company Damasteel and the impact on the current sales could be further investigated. 

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  • 38.
    Fjellström, Daniella
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Chowdhury, Ehsanul
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Osarenkhoe, Aihie
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Sjöberg, Sandra
    Sekyere, Bernard
    Critical role of cluster organisations to overcome SMEs´ liabilities of size, resources, newness, and foreignness in their internationalisation2022Ingår i: International Conference Proceedings: ICISET-22, ICBEN-22, LLESS-22 & IEMEL-22, 2022, Vol. 1, s. 111-112, artikel-id H1122509Konferensbidrag (Refereegranskat)
    Abstract [en]

    The purpose of the study is to find out how clusters can assist small- and medium enterprises (SME) s to expand their business to the international market. A qualitative approach was used in this study where the primary data was collected from five cluster organizations in the region of Gävleborg in Sweden with ten semi structured interviews with key personals in the five cluster organizations. The analysis was done with the help of concepts identified in the literature as well as new themes that was found in the empirical investigation.  The findings in this study have shown that the clusters can provide support to the SMEs to overcome obstacles related to capital, learning, innovation, networking, sales and strategy. The clusters can also help the SMEs in terms of sustainability. The weakest link is to help the SMEs to gain social capital where the clusters abilities are low. Each cluster has their niche competence so a collaboration within the clusters is required to help the SMEs in their international journey. The study extends the knowledge around the support system known as clustering as the study shows that only one cluster may not be able to help the SMEs in all the given areas required for their internationalization but a collaboration between clusters can help the SMEs to overcome most of the barriers towards internationalization. Future studies can focus on longitudinal research in this area to be able to follow the journey of the SMEs between the clusters but also to be able to capture and compare if the SMEs and cluster are experiencing the same pros and cons of the support system. We also suggest replicating this study in another region of Sweden to see if the results can be generalized or if it is a very local context regarding the help the SMEs can receive for internationalization. 

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  • 39.
    Fjellström, Daniella
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Chowdhury, Ehsanul
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Rupasinghe, Lasni
    Sustainable Innovation Challenges: Study of a Swedish MNC2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study aims to explore the external environment challenges that a multinational corporation (MNC) faces to adopt social innovation.

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  • 40.
    Fjellström, Daniella
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Osarenkhoe, Aihie
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Pettersson, Tobias
    Tadesse, Daniel
    The Role of Digitalization in SMEs’ Strategy Development: The Case of Sweden2020Ingår i: The Changing Role of SMEs in Global Business: Volume I: Paradigms of Opportunities and Challenges / [ed] Thrassou, A., Vrontis, D., Weber, Y., Shams, S.M.R., Tsoukatos, E., Palgrave Macmillan, 2020, 1, s. 65-88Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    The diffusion of digital technologies has enabled a notable transformation in firms’ boundaries, processes, structures, roles, and interactions. This digital revolution affects a company as a whole, thereby redefining its strategies, entrepreneurial processes, and governance mechanisms or structures. The aim of this study is to understand how digitalization affects small and medium-sized enterprises’ (SMEs’) marketing strategy. The study uses a qualitative approach with semi-structured interviews. The findings demonstrate that digital marketing tools demand few resources and have a positive effect on competitive advantage. The study contributes to our knowledge on how small enterprises develop strategy, showing that they focus on customer preferences. It also shows the benefits of SME digital marketing where digitalizing an enterprise’s marketing activities helps to reduce costs and increase dynamic capabilities to maintain competitive advantage.

  • 41.
    Fransson, Göran
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för utbildningsvetenskap, Utbildningsvetenskap.
    Norman, Fredrik
    Exploring how a digitally skilled teacher’s self-understanding influences his professional learning strategies. A research cooperation between a teacher and a researcher2021Ingår i: Teacher Development, ISSN 1366-4530, E-ISSN 1747-5120, Vol. 25, nr 4, s. 432-448Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The call for digitalisation in compulsory and upper secondary schools implies the need for teachers to pursue professional development. Here, teachers’ self-understanding may influence how they use, relate to and learn about digital technologies. 

    The purpose of this article is to explore how a teacher’s self-understanding influences his professional development activities and, in turn, is influenced by his learning. In focus for this case study is one upper secondary school teacher’s endeavour to enact digital technologies and find suitable strategies for professional learning. This teacher and a researcher formed a reflective research partnership to explore how, and whether, the teacher’s self-understanding and professional learning strategies influenced each other. Reflective conversations, reflective writings and theoretical inputs facilitated the analysis.

    The findings show, for example, how his task perception changed over time from an emphasis on teaching to a greater emphasis on improvement, supporting colleagues in their learning and contributing to the professionalisation of the teaching community. This in turn influenced him adopting a self-directed informal learning strategy. 

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  • 42.
    Ghahfarokhi, Sohil Shahabi
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Prasad, Sathyaveer
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Tayari, Danial
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap.
    Impact of Moisture Content on RFID Antenna Performance for Wood-Log Monitoring2011Ingår i: RFMTC11, Gävle, Sweden, 2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In recent years, the use of RFID technology has gained popularity in the timber industry for wood-log monitoring. Harvested wood-logs are stored for different time periods before being processed. As a result, the moisture content in the stored wood-logs varies compared to the freshly-cut wood and it must also be noted that the moisture content of freshly cut wood differs from one log to another. Apart from storage time period of wood-logs, the environmental factors such as temperature, rain, snow and sun also contributes to the variation in the moisture content of the wood-logs. This variation of the moisture content changes the dielectric constant of the wood and hence, influences the characteristics of the RFID antenna. In this paper the impact of variations in moisture content in wood and its effect on the performance of the RFID antenna are studied.

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  • 43.
    Gomes, João
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem.
    Bastos, Sílvio
    Instituto Politécnico de Castelo Branco, Portugal.
    Henriques, Mafalda
    Instituto Politécnico de Castelo Branco, Portugal.
    Diwan, Linkesh
    Olsson, Olle
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem. olle@solarus.com.
    Evaluation of the impact of stagnation temperatures in different prototypes of low concentration PVT solar panels2015Ingår i: ISES Solar World Congress 2015, Conference Proceedings, 2015, s. 993-1004Konferensbidrag (Refereegranskat)
    Abstract [en]

    Photovoltaic thermal (PVT) solar panels produce both thermal and electric power from the some area. This paper concerns a PVT design where the series connected strings of cells are laminated using silicone to an aluminium receiver where the heat transfer fluid flows. An evaluation of the impact of reaching high temperatures in the cell structural integrity and performance is presented. Eight small test receivers were made in which the following properties were varied: Size of the PV cells, type of silicone used to encapsulate the PV cells, existence of a strain relief between the cells, size of the gap between cells and type of cell soldering (line or point soldering). These test receivers were placed in an oven for one hour, under eight different monitored temperatures. The temperature of the last round was set at 220°C which well exceeds the highest temperature the panel design can reach. Before and after each round in the oven, the following tests were conducted to the receivers: Electroluminescence (EL) test, IV-curve, diode function, and visual inspection. The test results showed that the receivers made with the transparent silicone and strain relief between cells experienced less micro-cracks and lower degradation in maximum power. No prototype test receiver lost more than 30% of its initial power, despite the large cell breakage shown in some receivers. Prototype receivers with transparent (softer) silicone showed much far less cracks and power decrease when compared to red (harder) silicone receivers. As expected, larger cells are more prone to develop micro-cracks after exposure to thermal stress. Additionally, existing micro-cracks tend to grow in size into larger micro-cracks relatively fast with thermal stress. The EL imaging taken during our experiment leads us to observe that it seems far easier for existing cracks to expand than for new cracks to appear.

  • 44.
    Gonzales Fuentes, Lee
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap. Vrije Universiteit Brussel.
    Barbe, Kurt
    Vrije Universiteit Brussel.
    Van Moer, Wendy
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik. Vrije Universiteit Brussel.
    Björsell, Niclas
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Cognitive radios: discriminant analysis finds the free space2012Ingår i: 2012 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), New York: IEEE conference proceedings, 2012, s. 2242-2247Konferensbidrag (Refereegranskat)
    Abstract [en]

    Spectrum sensing is an essential pre-processing step for cognitive radio technology. This paper presents a novel method to detect the significant spectral components in measured nonflat spectra, and to estimate the magnitude of the spectral components. Furthermore, the probability that the spectral component was incorrectly classified is available. The algorithm is able to detect the presence or absence of signals in any kind of spectrum since no prior knowledge about the measured signal is needed. Hence, this method becomes a strong basis for a high-quality operation mode of cognitive radios. Simulation results prove the advantages of the presented technique.

  • 45.
    Grylin, Hanna
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Juridik.
    Torstensson, Sofia
    Beräkning av skogsavdragsutrymmet vid fastighetsreglering av fastigheter med skogsmark2023Ingår i: Svensk skattetidning, ISSN 0346-2218, nr 2, s. 95-100Artikel i tidskrift (Övrigt vetenskapligt)
  • 46.
    Hartwig, Fredrik
    et al.
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    Hansson, Emil
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi.
    Nielsen, Linn
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi.
    Sörqvist, Patrik
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi.
    The relation between auditing and accounting timeliness in Swedish private firms2023Ingår i: Journal of Financial Regulation and Compliance, ISSN 1358-1988, E-ISSN 1740-0279, Vol. 31, nr 3, s. 379-396Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The purpose of this study is to examine the relationship between auditing/non-auditing and accounting timeliness among Swedish private firms.

    Design/methodology/approach: This paper uses regression analysis to test the relationship between auditing and two measurements of timeliness; lead time and late filing. The sample consists of Swedish private firms.

    Findings: The paper finds that audited firms, when compared with unaudited firms, are significantly less timely. Moreover, greater profitability was associated with more timeliness but only for audited firms. The results also show that firms being audited by a big 4-auditor are significantly timelier than firms being audited by a non-big 4 auditor.

    Practical implications: The findings in this paper suggests that one aspect of accounting quality, timeliness, does not seem to benefit from auditing in a Swedish context. There is a debate about whether the threshold levels in Sweden should be raised so that more firms voluntarily can opt out of audit. Those opposing a raised threshold level claim that auditing has positive effects on accounting quality and consequently that a raised level would have adverse effects. The findings in this paper do not support such a claim.

    Originality/value: Little is known about timeliness in private firms compared to public firms and this paper fills that void. Contrary to prior research, findings show that unaudited firms in a Swedish regulatory setting actually are timelier than their audited counterparts. This questions one of the (presumed) benefits of auditing and should stimulate more research on this issue.

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  • 47.
    Hilmola, Olli-Pekka
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för industriell ekonomi, industridesign och maskinteknik, Industriell ekonomi.
    Li, Haihan
    Department of Industrial Engineering and Management, University of Gavle, Gavle, Sweden.
    Hilletofth, Per
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för industriell ekonomi, industridesign och maskinteknik, Industriell ekonomi. Högskolan i Gävle, Centrum för logistik och innovativ produktion.
    Fjellström, Daniella
    Högskolan i Gävle, Akademin för utbildning och ekonomi, Avdelningen för ekonomi, Företagsekonomi.
    A Supply Chain Perspective Reviewing Shoring Cases2023Ingår i: Operations and Supply Chain Management, ISSN 1979-3561, Vol. 16, nr 4, s. 524-534Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Shoring trend of supply chains has changed over the decades. In the initial stages it mostly concerned about offshoring, however, recently it has changed to reshoring. This study focuses on the mainstreams of shoring case studies from the supply chain perspective with a systematic literature review. We identified 22 supply chain shoring cases from the initial pool of thousands of supply chain case studies. Publishing activity was increasing until 2010, but thereafter it has been sporadic. It could be concluded that shoring always contains numerous risks. As failures were also reported, it is simply so that not too much weight should be placed on costs and locating only to one country. Based on research works, global sourcing will continue in the future, however, new locations and practices shall prevail. Single-sided reshoring supply chains back to developed economies is not the only answer due to costs and supply chain tensions.

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  • 48.
    Ikram, Amna
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Beckman, Claes
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Irmscher, Stefan
    Laird Technologies.
    Design and Development of a Multiband Loop Antenna for Cellular Mobile Handsets2011Ingår i: IEEE International Workshop on Antenna Technology, 2011, s. 251-254Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents the results of the design and characterization of a loop antenna for mobile cellularh andsets. Based on a typical smart phone antenna geometry, a bottom mounted off-ground meanderline loop antennah as been designed, which has the potential to cover the required bands of Long Term Evolution (LTE) US 700MHz, Global System for Mobile communications (GSM) 824-960MHz, Digital Communication System (DCS) 1710-1880 MHz, Personal Communication Services PCS 1850-1990 MHz, Universal Mobile Telecommunications System (UMTS) 1920-2170MHz and LTE EU 2500. The carrier volume of 50*10*5mm3 and ground plane of length 100mm is used. The carrier permittivity εr is 2.66 and loss tangent tanδ is 0.00629 @2.44GHz. Copper is used as a metal part of the antenna having conductivity of 5.8e7 S/m and thickness of 0.1mm. The antenna supports balanced and unbalanced modes for certain frequencies. It is highly efficient in terms of small volumetric size for a given bandwidth of operations. The antenna generates weak near field electric and magnetic fields complying with the standards for the Specific Absorption Rate (SAR) and Hearing Aid Compability (HAC). The impact of body effects on the radiation efficiency has been quantified. The measured results of the prototype are in good agreement with the simulated results.

  • 49. Jans, Jessica
    et al.
    Falk-Brynhildsen, Karin
    University of Örebro.
    Salzmann-Erikson, Martin
    Högskolan i Gävle, Akademin för hälsa och arbetsliv, Avdelningen för vårdvetenskap, Med-Vårdvetenskap.
    Nurse anesthetists’ reflections and strategies when supervising master's students2021Ingår i: Nurse Education in Practice, ISSN 1471-5953, E-ISSN 1873-5223, Vol. 54, artikel-id 103120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective

    The objective was to describe registered nurse anesthetists’ reflections and strategies in relation to supervision of specialist nursing students in anesthetic care.

    Background

    In anesthesiology care, registered nurse anesthetists work with advanced care in a high-technology environment. The complexity of working with production requirements, time pressure and patient safety creates great challenges. Registered nurse anesthetists have a unique position and are responsible for the patient’s life during surgery. At the same time, they must supervise students without risking patient safety. Little research to date has focused on the clinical supervisory role in this context.

    Design

    A qualitative design was used.

    Methods

    The data were collected in 2018 from qualitative interviews with a purposive sample of twelve student registered nurse anesthetists from a large hospital in Sweden. The data were analyzed using content analysis.

    Results

    The results demonstrated that the dual role of registered nurse anesthetist and supervisor was experienced as satisfying, important and promoting development, although it also involved several challenges. Creating opportunities for supervision and learning in perioperative care improved supervisors’ prerequisites for supporting students and helping them develop. Being a supervisor was also rewarding, and given the interplay with students, supervision was viewed as a process of mutual growth.

    Conclusion

    By focusing on students and their learning, we can help produce well-qualified registered nurse anesthetists who have positive experiences of the workplace and who want to stay in their profession.

  • 50.
    Javashvili, Otar
    et al.
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för elektronik, matematik och naturvetenskap, Elektronik.
    Andersson, Daniel
    Radarbolaget.
    New method for design implementation of Vivaldi antennas to improve its UWB behaviour (EuCAP 2010)2010Ingår i: Proceedings of the Fourth European Conference on Antennas and Propagation: EuCAP 2010 - The 4th European Conference on Antennas and Propagation, 2010, artikel-id 5505298Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this paper is to investigate the parameters of one of the UWB Sensors, called Vivaldi Antenna, and to propose the new ways how they can be improved. As a practical implementation of the sensor, the UWB radar for wall penetrating applications with impulse excitation was utilized. For wall penetration low frequency (0.3 – 8 GHz) supporting UWB signals are required. Within the scope of this project, the Vivaldi antenna parameters are improved in order to optimize the radiation bandwidth with an usable gain response along the whole operating band, including lower frequencies. It also automatically leads to the optimization of the size of the antenna. In addition, an investigation of the phase linearity and UWB behavior of the antenna was carried out.

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