| 1. |
- Saberi, Azim, et al.
(författare)
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Accuracy assessment and improvement of SRTM, ASTER, FABDEM, and MERIT DEMs by polynomial and optimization algorithm : A case study (Khuzestan Province, Iran)
- 2023
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Ingår i: Open Geosciences. - : De Gruyter Open. - 2391-5447. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Satellite digital elevation models (DEMs) are used for decision-making in various fields. Therefore, evaluating and improving vertical accuracy of DEM can increase the quality of end products. This article aimed to increase the vertical accuracy of most popular satellite DEMs (i.e., the ASTER, Shuttle Radar Topography Mission [SRTM], Forest And Buildings removed Copernicus DEM [FABDEM], and Multi-Error-Removed Improved-Terrain [MERIT]) using the particle swarm optimization (PSO) algorithm. For this purpose, at first, the vertical error of DEMs was estimated via ground truth data. Next, a second-order polynomial was applied to model the vertical error in the study area. To select the polynomial with the highest accuracy, employed for vertical error modeling, the coefficients of the polynomial have been optimized using the PSO algorithm. Finally, the efficiency of the proposed algorithm has been evaluated by other ground truth data and in situ observations. The results show that the mean absolute error (MAE) of SRTM DEM is 4.83 m while this factor for ASTER DEM is 5.35 m, for FABDEM is 4.28, and for MERIT is 3.87. The obtained results indicated that the proposed model could improve the MAE of vertical accuracy of SRTM, ASTER, FABDEM, and MERIT DEMs to 0.83, 0.51, 0.37, and 0.29 m, respectively.
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| 2. |
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| 3. |
- Broman, Lars
(författare)
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Om Centrum för solenergiforskning SERC och Europeiska solingenjörsskolan ESES : En personlig betraktelse
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Solar Energy Research Center SERC started at Högskolan Falun Borlänge – now Dalarna University - in November 1984 as the first research center at any Swedish University College. Gradually it has grown from a small and not always by its environment appraised institution into Sweden's leading research center in its field. European Solar Engineering School ESES was originally intended to be established on the Italian island of Capri, but began as a Master Program at Dalarna University at the beginning of the fall semester 1999. ESES attracts students from all over the world and has today a reputation of one of the world's best educations in its field. My own role was to initiate SERC and ESES and being instrumental in their respective first years of development, while their continued growth has depended highly on my former colleagues, still active at Dalarna University.
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| 4. |
- Chatzigiannakou, Maria Angeliki, et al.
(författare)
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Numerical analysis of an Uppsala University WEC deployment by a barge for different sea states
- 2020
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Ingår i: Ocean Engineering. - : Elsevier BV. - 0029-8018 .- 1873-5258. ; 205
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Tidskriftsartikel (refereegranskat)abstract
- Wave energy converters (WECs) have been deployed onshore, nearshore, and offshore to convert ocean wave movement into electricity. The exploitation of renewable energy sources has restrictions; in the case of wave energy, high installation, maintenance, and decommissioning costs have limited their commercial use. Moreover, these offshore operations can be compromised by safety issues. This paper draws attention to offshore operation safety of a WEC developed by Uppsala University. Specifically, this paper investigates what sea states are suitable for the safe deployment of a WEC from a barge. This study follows recommendations in DNV-RP-H103 for analysis of offshore operations, namely lifting through the wave zone. ANSYS Aqwa is used to find hydrodynamic forces acting on a typical barge, using frequency domain analysis. Based on these hydrodynamic simulation results and methodology given in DNV-RP-H103, tables are created to show the sea states that would allow for the safe installation of a WEC using a typical barge. Considered sea states have significant wave heights varying between 0 m and 3 m and the wave zero crossing periods varying between 3 s and 13 s. The WEC submersions are considered between 0 m and 7 m, i.e. when the WEC is in the air until it is fully submerged. © 2020 Elsevier Ltd
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| 5. |
- Roxberg, Åsa, 1953-, et al.
(författare)
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Space and place for health and care
- 2020
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Ingår i: International Journal of Qualitative Studies on Health and Well-being. - Abingdon : Taylor and Francis Ltd.. - 1748-2623 .- 1748-2631. ; 15:sup1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This discussion paper aims to contribute to a greater understanding of the state of the art of research engaged with conceptual matters of space and place for health and care. Method: The authors, who represent a variety of academic disciplines, discuss and demonstrate the conceptual recognition of space and place in research in health and caring sciences building upon own work and experience. Results: To explore the concepts of space and place for health and care is a research pursuit of utmost importance, and should be made through transdisciplinary research collaborations, whereby spatial theories from various disciplines could be communicated to cultivate truly novel and well-informed research. Furthermore, engaging with relational and topological perceptions of space and place poses methodological challenges to overcome in future research on health and care. Conclusions: We argue that there is a need for accelerating spatially informed research on health and care that is informed by current theories and perspectives on space and place, and transdisciplinary research collaborations are a means to achieving this. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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| 6. |
- Björner Brauer, Hanna, et al.
(författare)
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The Ghost in the Heat Pump : Examining social flexibility potential in thermal comfort practices through an experiment of remote-controlled heating in detached houses
- 2023
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Ingår i: Conference Proceedings BEHAVE 2023 the 7th European Conference on Behaviour Change for Energy Efficiency. - : European Energy Network; Netherlands Enterprise Agency. ; , s. 240-251
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Konferensbidrag (refereegranskat)abstract
- Utilizing energy flexibility in households through smart steering of appliances has received attention as one way to reduce power peaks and adapt demand to a renewable energy system. Heating is a big part of the electricity consumption in households, and heat pump technology is growing in popularity for heating detached houses. While there is ongoing research calculating the technical potential for energy flexibility from heat pumps, few studies combine remote control of heat pumps with qualitative research on how households experience this control. The purpose of this study is to find out how long-term steering of heat pumps is experienced by households, how it affects their heating practices, and how they make sense of remote steering as a service. The data originates from an interdisciplinary project combining a field trial where heat pumps of selected Swedish households were remotely controlled for two winter periods, with qualitative interviews with the households. We conducted interviews with 12 participants, before and after the trial.The results show that households were overall positive towards offering flexibility through remote-controlled heat pumps, and that the steering of the heating blended well with normal temperature variation associated with having a villa in Sweden. However, the respondents were mystified by the procedure, which created a ghost in the heat pump. Furthermore, remote steering as a service comes with challenges related to reliability, security, and agency over the heat pump. Important social conditions for adopting flexibility through remote steering of heat pumps are discussed.
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| 7. |
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| 8. |
- Eshagh, Mehdi, Professor, 1977-, et al.
(författare)
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A case study on displacement analysis of Vasa warship
- 2018
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Ingår i: Journal of Geodetic Science. - : DE GRUYTER POLAND SP ZOO. - 2081-9919 .- 2081-9943. ; 8:1, s. 43-54
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Tidskriftsartikel (refereegranskat)abstract
- Monitoring deformation of man-made structures is very important to prevent them from a risk of collapse and save lives. Such a process is also used for monitoring change in historical objects, which are deforming continuously with time. An example of this is the Vasa warship, which was under water for about 300 years. The ship was raised from the bottom of the sea and is kept in the Vasa museum in Stockholm. A geodetic network with points on the museum building and the ship's body has been established and measured for 12 years for monitoring the ship's deformation. The coordinate time series of each point on the ship and their uncertainties have been estimated epoch-wisely. In this paper, our goal is to statistically analyse the ship's hull movements. By fitting a quadratic polynomial to the coordinate time series of each point of the hull, its acceleration and velocity are estimated. In addition, their significance is tested by comparing them with their respective estimated errors after the fitting. Our numerical investigations show that the backside of the ship, having highest elevation and slope, has moved vertically faster than the other places by a velocity and an acceleration of about 2 mm/year and 0.1 mm/year(2), respectively and this part of the ship is the weakest with a higher risk of collapse. The central parts of the ship are more stable as the ship hull is almost vertical and closer to the floor. Generally, the hull is moving towards its port and downwards.
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| 9. |
- Grankvist, Gunne, 1963-, et al.
(författare)
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Values and willingness-to-pay for sustainability-certified mobile phones
- 2019
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Ingår i: International Journal of Sustainable Development and World Ecology. - : Informa UK Limited. - 1350-4509 .- 1745-2627. ; 26:7, s. 657-664
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated whether endorsement of personal values is associated with willingness to pay more for mobile phones with an environmental or social sustainability label. Participants were students in Sweden, Norway and Germany. A self-report inventory was used to measure willingness to pay and the importance attached to values of Schwartz's circular model. In Sweden and Norway, participants were willing to pay, on average, 18% extra for a mobile phone with labels for environmental or social sustainability. In Germany, the corresponding share was 12%. To strive for self-enhancement values, that is, social status and prestige, as well as control and dominance over people and resources, was associated with a lower willingness to pay for mobile phones with labels for environmental or social sustainability in all three countries. Furthermore, women were willing to pay more than men for mobile phones with both kinds of sustainability labels. In Sweden and Norway, participants were, on average, willing to pay more for a mobile phone with a label for social sustainability compared to a mobile phone with a label for environmental sustainability. © 2019 Informa UK Limited, trading as Taylor & Francis Group.
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| 10. |
- Isaksson, Charlotta, 1974-
(författare)
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Learning for lower energy consumption
- 2014
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Ingår i: International Journal of Consumer Studies. - : Wiley. - 1470-6423 .- 1470-6431. ; 38:1, s. 12-17
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Tidskriftsartikel (refereegranskat)abstract
- Energy-efficient technologies are not just objects that might enable households to carry out more sustainable practices; they are tools, and using them effectively requires certain skills and knowledge. Households' difficulties in handling home heating and hot water technologies in particular have been highlighted as an obstacle to meeting energy conservation objectives. This has given rise to calls for improved support based on how the households define their activities and handle these technologies. By deploying a socio-cultural theory of learning and using in-depth interviews with households that have recently purchased renewable heating systems, this paper examines various situations in which people have learnt to use the technologies, and it discusses lessons learnt that may be useful for developing support. The results demonstrate three common learning approaches and identify situations where the learning process runs smoothly and where it does not. The conclusions suggest strategies for helping households overcome the resistance embedded in the interaction with the technologies, and they highlight the importance, when developing support, of starting with what creates meaning in various situations.
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