| 1. |
- Granlund, Alexander, et al.
(author)
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Evaluation of Local Conditions and Their Impact on Bifacial PV Performance at High Latitude
- 2022
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Conference paper (peer-reviewed)abstract
- Different conditions such as module orientation, ground albedo, shading and latitude are known to affect the performance of bifacial photovoltaic modules. We evaluate bifacial performance for one year at a site located at 65°N through comparison of measured and simulated front and back side plane-of-array irradiation. Each investigated module has a different azimuth, tilt, and exposure to shading from the surroundings. Local shading is found to severely impact the energy yield of the site in general, and individual modules to a varying degree depending on their location and orientation. Proper shading analysis appears to be required in the planning phase of a bifacial photovoltaic installation to accurately calculate the expected energy yield. The bifacial gain of the modules with azimuths in the east–west sector is found to span a range from 16 % to approximately the bifaciality factor, depending on the orientation. To fully utilize the potential of bifacial photovoltaics, this variability also needs to be carefully considered when planning and building bifacial photovoltaic installations.
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| 2. |
- Granlund, Alexander, et al.
(author)
-
Evaluation of Snow Removal Methods for Rooftop Photovoltaics
- 2022
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Conference paper (peer-reviewed)abstract
- Avoiding snow on photovoltaic (PV) installations is motivated for two reasons: to decrease power losses from shading, or to decrease mechanical loads to avoid damage to the PV-installation and the underlying construction. We experimentally investigated the effectiveness and suitability of four different snow removal methods at our facility in the north of Sweden (Piteå, 65°N), throughout three winters. The layout of a PV installation and the underlying roof, together with meteorological conditions and snow characteristics, impact which methods are best suited for snow removal. A simple roof rake with a rectangular toolhead works well when the snowpack is compact and not too thick, whereas a roof rake with a slide works better when the snow is dry and packed. Neither the investigated passive hydrophobic surface coatings, nor the active forward bias electrical heating methods induced shedding of the accumulated snowpack in our experiments without additional intervention. At our test facility in Piteå, the roof rake with a slide was the most effective and user-friendly snow removal. Despite maximum snow loads of approximately 1 kPa, far below the modules’ rating, cell damage was observed for both snow removal groups (except for the slide roof rake group) and the control group.
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| 3. |
- Nguyen, Björnborg, 1992, et al.
(author)
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Application and evaluation of direct sparse visual odometry in marine vessels
- 2022
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In: IFAC-PapersOnLine. - : Elsevier BV. - 2405-8963. ; 55:31, s. 235-242
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Conference paper (peer-reviewed)abstract
- With the international community pushing for a computer vision based option to the laws requiring a look-out for marine vehicles, there is now a significant motivation to provide digital solutions for navigation using these envisioned mandatory visual sensors. This paper explores the monocular direct sparse odometry algorithm when applied to a typical marine environment. The method uses a single camera to estimate a vessel's motion and position over time and is then compared to ground truth to establish feasibility as both a local and global navigation system. Whilst it was inconsistent in accurately estimating vessel position, it was found that it could consistently estimate the vessel's orientation in the majority of the situations the vessel was tasked with. It is therefore shown that monocular direct sparse odometry is partially suitable as a standalone navigation system and is a strong base for a multi-sensor solution.
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| 4. |
- Petersson, Anna, et al.
(author)
-
Interior design dilemmas in a shared room of silence.
- 2020
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In: Material Religion: the journal of objects, art and belief. - : Informa UK Limited. - 1743-2200. ; 16:2, s. 213-235
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Journal article (peer-reviewed)abstract
- This text sheds light on the delicate practice of including different religious as well as nonreligious expressions in a shared room. The effects of design decisions in a “room of silence” at a Swedish hospital are studied over a transitional period of renovation of the space. We observe the impact of materiality in the room’s establishment, renovation, and usage, and show how the room’s interior design, its decor and objects, are conditioned by ritual acts as well by practical and spontaneous place-making processes. By following how the negotiations of the interior space relate to presupposed separations of aesthetic and religious ideals, we see how the design of a room of silence can allow several religious groups to comfortably use one common room; but also how design can cause clashes between different interests and how materiality is forced in the end to advice a clear spatial distinction between different types of usage in the room.
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| 5. |
- Granlund, Alexander, et al.
(author)
-
The Influence of Module Tilt on Snow Shadowing of Frameless Bifacial Modules
- 2019
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Conference paper (other academic/artistic)abstract
- In this study, frameless bifacial modules’ performance in a boreal climate is examined, with a focus on snow coverage and snow clearance for different module tilt angles. A group of ten bifacial modules at different tilt angles located in northern Sweden at latitude 65°N were studied during the first months of 2019. It was shown that modules mounted at 0 and 15° tilt was covered the most by snow and 80 and 90° the least. All other modules, mounted at 25-70° tilt, showed mostly similar results in snow coverage and removal. All modules were subjected to snow coverage from January to March. In January no considerable energy output was observed for any module. In February and March modules with tilt angles of 0 and 15° had a lower energy output than the other modules, for which no considerable differences were observed. In April, when no snow coverage occurred, the module mounted at 45° had the largest energy output and in May, 25-35° performed the best. For the entire period of January-May the modules at 35-45° output the most energy.
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| 6. |
- Petersson, Anna Malou, et al.
(author)
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Developing an ideation method to be used in cross-functional inter-organizational teams by means of action design research
- 2018
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In: Research in Engineering Design. - : Springer. - 0934-9839 .- 1435-6066. ; 29:3, s. 433-457
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Journal article (peer-reviewed)abstract
- Using ideation methods in an optimal way has a great potential to increase the number of ideas which a team can contribute during the conceptual phase of product development in industry. Previous studies on ideation methods have been mainly statistical studies in a laboratory setting. In the present study, however, the aim was to develop tailor-made ideation methods in a specific context, among actors on a deregulated railway market, through close interaction between researchers and engineers in a real-world context. Considering previous relevant research on ideation methods, associative memory models and the findings from tests of established ideation methods performed in the same group, a number of preliminary design principles were formulated and implemented in an ideation method that combines individual phases of rotational and gallery viewing with phases of verbal group interaction. The method was tested and refined in a cross-functional inter-organizational group comprising participants from different actors in the railway sector. Besides its provision of qualitative and quantitative test results, the present study has considered the opinions of the participants in detail, which can give important insights into the factors determining whether such a method will be implemented in industry. The participants found the method to be more useful and to generate more ideas that could be used in practice compared to the established ideation methods which they had tried. The learning derived from the specific case was formalized into a number of design principles for ideation methods to be used in cross-functional inter-organizational groups.
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| 7. |
- Petersson, Anna Malou
(author)
-
Collaborative conceptual design methods in the context of the Swedish deregulated railway market : From the perspectives of maintenance, infrastructure management, product provision, and research
- 2017
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Doctoral thesis (other academic/artistic)abstract
- As a result of the deregulation of the Swedish railway market, the differentfunctions involved during the life cycle of railway products have been spreadout over different actors. The trigger for the work presented in this thesis wasthe insight that, since function-specific knowledge of the railway in Swedenbelongs to different organizations, special efforts would be needed to achieve aholistic picture of a railway product during the conceptual design phase. However,there is a lack of methods developed for groups with participants fromdifferent organizations possessing different functional knowledge about a product.The overall aim of the research for this thesis was therefore to develop anideation method and a concept selection method specifically for groups actingin the context of the Swedish deregulated railway market, with members fromdifferent organizations with different functional knowledge. By means of actiondesign research, the methods were developed within the scope of a researchproject involving four different actors on the Swedish railway market.The project group tested Method 635, the gallery method and the SIL method.Overall, the gallery method was most popular and the SIL method leastpopular among the participants. Method 635 was found to have a considerablyhigher idea and concept generation rate than the gallery and SIL methods.The developed ideation method combines the rotational viewing of generatedideas in the group and gallery viewing with steps of verbal interaction wherethe group members take turns to present and comment on generated ideas. Theproject group regarded the developed method as the best method of all themethods which they had tried, and it outperformed the other methods with regardto the total number of generated concepts and ideas. The views of the projectgroup on the method correlated positively to the views of participants takingpart in field tests of the method.The developed concept selection method combines refined versions of theprocedures for topic clarification, goal specification, requirement specificationand concept screening developed by Pahl and Beitz with a concept scoring procedurebased on the life cycle and societal costs associated with each conceptthat fulfils the stated requirements.The most important effect of the composition of the group was found to bethe wide range of viewpoints on the topic at hand that the representative groupof different relevant actors was able to provide.
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| 8. |
- Petersson, Anna Malou, et al.
(author)
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Ideation methods applied in a cross-functional inter-organizational group : an exploratory case study from the railway sector
- 2017
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In: Research in Engineering Design. - : Springer. - 0934-9839 .- 1435-6066. ; 28:1, s. 71-97
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Journal article (peer-reviewed)abstract
- The conceptual design phase is a critical step, since it influences the subsequent steps during product development with regard to cost, quality and performance. Previous research has focused on cross-functional teams within an organization. However, many product development projects benefit from the participation of members from different organizations, not least during the conceptual design phase of technical products, where it is essential to consider different aspects of the product-to-be. Therefore, we conducted an in-depth case study of a cross-functional inter-organizational group testing ideation methods in a real-life setting within a development project in the railway sector. The group comprised participants from an infrastructure manager, a supplier, a maintenance contractor and research bodies. The tested ideation methods were Method 635, the gallery method and the SIL method. The participants found working in a cross-functional inter-organizational group to be beneficial both during the group-analysis of the topics and during the generation of ideas on how to address the ideation topic. Applying the ideation methods to the ideation topics facilitated the sharing of information between participants, and the diversity of the group manifested itself in several ways during ideation. Overall, the gallery method was most popular, and the SIL method was least popular among the participants.
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| 9. |
- Petersson, Anna, et al.
(author)
-
Urban cemetery animals : An exploration of animals’ place in the human cemetery
- 2017
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In: Mortality. - : Taylor & Francis. - 1357-6275 .- 1469-9885. ; , s. 1-18
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Journal article (peer-reviewed)abstract
- This paper investigates the place of animals in the contemporary Swedish human cemetery. It does this by looking at how animals are admitted to cemeteries – alive and dead, above and below ground, physically as well as symbolically. The aim is to shed light on the various ways that animals are experienced and treated in the cemetery, and to explore how this both reflects our changing attitudes to animals and our changing attitudes to death. The paper draws on the findings from a qualitative interview study carried out at the Eastern Cemetery in Malmö, Sweden, and a follow-up study of a turtle pond, in Malmö-Limhamn Cemetery. Two different perspectives relating to animals in the cemetery were common to these studies: (1) the liminal role of the companion animal; and (2) aesthetics and care in relation to wild and domesticated animals. The two perspectives, considered as findings in their own right, are used in this paper as a foundation for discussing questions relating to how urban cemetery animals can enrich the cemetery environment and increase the importance of urban cemeteries today and in the future.
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| 10. |
- Petersson, Anna Malou, et al.
(author)
-
Applying action design research (ADR) to develop concept generation and selection methods
- 2016
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In: Procedia CIRP. - : Elsevier BV. - 2212-8271 .- 2212-8271. ; 50, s. 222-227
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Journal article (peer-reviewed)abstract
- During conceptual design, concept generation and selection methods can be used to facilitate the generation of new ideas and the selection of the most promising suggestions. The present paper is an effort to understand better how action design research can be utilized to develop such methods. Using action design research, methods were developed through iterative cycles of building, testing and evaluation in the context of a deregulated railway market, through a close collaboration between actors from industry, a government agency and academia. The approach was found to be feasible and to provide generalization of the context-specific findings through the formulation of design principles.
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