| 1. |
- Alklind Taylor, Anna-Sofia, 1975-, et al.
(författare)
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Guardian Angel : Using Lighting Drones to Improve Traffic Safety, Sense of Security, and Comfort for Cyclists
- 2023
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Ingår i: Lecture Notes in Computer Science. - Cham : Springer. - 9783031480461 - 9783031480478 ; , s. 209-223
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Konferensbidrag (refereegranskat)abstract
- Active mobility, such as biking, faces a common challenge in Swedish municipalities due to the lack of adequate lighting during the dark winter months. Insufficient lighting infrastructure hinders individuals from choosing bicycles, despite the presence of well-maintained bike paths and a willingness to cycle. To address this issue, a project has been undertaken in the Swedish municipality of Skara for an alternative lighting solution using drones. A series of tests have been conducted based on drone prototypes developed for the selected bike paths. Participants were invited to cycle in darkness illuminated by drone lighting and share their mobility preferences and perception. This paper summarizes the users’ perception of drone lighting as an alternative to fixed lighting on bike paths, with a special focus on the impact on travel habits and the perceived sense of security and comfort. Most participants were regular cyclists who cited bad weather, time, and darkness as significant factors that deterred them from using bicycles more frequently, reducing their sense of security. With drone lighting, the participants appreciated the illumination’s moonlight-like quality and its ability to enhance their sense of security by illuminating the surroundings. On the technology side, they gave feedback on reducing the drone’s sound and addressing lighting stability issues. In summary, the test results showcase the potential of drone lighting as a viable alternative to traditional fixed lighting infrastructure, offering improved traffic safety, sense of security, and comfort. The results show the feasibility and effectiveness of this innovative approach, supporting transformation towards active and sustainable mobility, particularly in regions facing lighting challenges.
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| 2. |
- André, Alann, 1980, et al.
(författare)
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Application of fracture mechanics to predict the failure load of adhesive joints used to bond CFRP laminates to steel members
- 2012
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Ingår i: Construction and Building Materials. - : Elsevier BV. - 0950-0618 .- 1879-0526. ; 27:1, s. 331-340
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Tidskriftsartikel (refereegranskat)abstract
- The use of bolted or welded elements to upgrade metallic structures has been a common practice for many years. Moreover, the use of adhesively bonded carbon fiber reinforced polymer (CFRP) laminates, as an alternative method, has attracted a great deal of attention in recent years. One important aspect of the design of adhesive joints used to bond CFRP laminates to steel substrates is the determination of the properties of the CFRP/adhesive/steel interfaces, which have not yet been established in codes or standards. The purpose of this paper is experimentally to determine the fracture properties of the adhesive material and to evaluate the accuracy of numerical methods using this information, in order to predict the strength of adhesive joints in steel members bonded with CFRP laminates. The results from four series of experimental tests are compared with numerical results and discussed in terms of load-bearing capacity and failure modes.
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| 3. |
- Belov, Ilja, et al.
(författare)
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Fin‐Tube and Plate Heat Exchangers : Evaluation of Transient Performance
- 2017
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Ingår i: 18th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE). - : IEEE. - 9781509043446 - 9781509043439 - 9781509043453
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Konferensbidrag (refereegranskat)abstract
- A methodology for evaluation of transient performance of, and comparison between plate heat exchanger and plate-fin-and-tube heat exchanger was developed and realized, including experiment and 3-D simulation. Heat transfer from water to a gas medium was addressed. The heated gas volume was the same for both heat exchanger designs. This was achieved by placing the plate-fin-and-tube heat exchanger into enclosure. The volume average temperature of the gas as function of time was computed. Estimated material cost for the studied designs was at least seven times lower than for the stainless steel plate heat exchanger. The performance of the selected plate-fin-and-tube heat exchanger design was found comparable to the plate heat exchanger, when both fin and tube materials were set to Al, and the enclosure was a light-weight thermal insulator. Transient behavior of the studied heat exchangers should be of interest for micro-grid applications, but also for thermal management in electronic cabinets and data centers.
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| 4. |
- Bouguelia, Mohamed-Rafik, 1987-, et al.
(författare)
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Mode tracking using multiple data streams
- 2018
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Ingår i: Information Fusion. - Amsterdam : Elsevier BV. - 1566-2535 .- 1872-6305. ; 43, s. 33-46
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Tidskriftsartikel (refereegranskat)abstract
- Most existing work in information fusion focuses on combining information with well-defined meaning towards a concrete, pre-specified goal. In contradistinction, we instead aim for autonomous discovery of high-level knowledge from ubiquitous data streams. This paper introduces a method for recognition and tracking of hidden conceptual modes, which are essential to fully understand the operation of complex environments, and an important step towards building truly intelligent aware systems. We consider a scenario of analyzing usage of a fleet of city buses, where the objective is to automatically discover and track modes such as highway route, heavy traffic, or aggressive driver, based on available on-board signals. The method we propose is based on aggregating the data over time, since the high-level modes are only apparent in the longer perspective. We search through different features and subsets of the data, and identify those that lead to good clusterings, interpreting those clusters as initial, rough models of the prospective modes. We utilize Bayesian tracking in order to continuously improve the parameters of those models, based on the new data, while at the same time following how the modes evolve over time. Experiments with artificial data of varying degrees of complexity, as well as on real-world datasets, prove the effectiveness of the proposed method in accurately discovering the modes and in identifying which one best explains the current observations from multiple data streams.
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| 5. |
- Brolin, Anna, et al.
(författare)
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Kitting as an information source in manual assembly
- 2012
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Ingår i: Advances in Ergonomics in Manufacturing. - : CRC Press. - 9781439870396 - 9780429107603 - 143987039X ; , s. 346-353
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Bokkapitel (refereegranskat)abstract
- In manual assembly, a strategy to meet the goal of efficient production is the increased use of kitting as a material supply principle. Even though kitting is already implemented in industry, there are still uncertainties regarding the effects of introducing kits, particularly from a human factors perspective.This paper presents initial steps in the development of a method to be used for the evaluation of kitting. This from an information source point of view and for studying effects related to productivity and quality. The methodology is projected to act as a foundation for how to carry out a subsequent comprehensive case study. The purpose of the case study is to explore how kitting affects the cognitive workload compared to the ordinary material rack combined with part numbers used in the current manufacturing industry. This is done by measuring productivity; time spent on assembling a product, and quality; number of assembly errors. One step in the methodology development process, which is described in this paper, was to conduct a pilot study, primarily to test the methodology related to the selection of measurement parameters, as well as for getting experiences from running the methodology with real test subjects.
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| 6. |
- Brolin, Anna, et al.
(författare)
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Use of kitting to ease assemblers' cognitive workload
- 2011
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Ingår i: Proceedings of NES2011 September 18—21, 2011 Oulu, Finland. - : University of Oulu. - 9789514295416 ; , s. 77-82
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Konferensbidrag (refereegranskat)abstract
- The higher level of product variation in the automotive industry leads to an increasing workload for the assembler that has to search, fetch and assemble all the variants. This puts high demands on the information that is given to the assembler to fulfil the assembly task. This paper describes the impact of information overload and sources, and their influence on the assembler. Through observations conducted in the Swedish automotive industry, the study has shown that the assembly personnel perceive the kit as structured information and that structured kits are able to present distinct information at a certain place to the assembler, which in turn reduces the searching, resulting in decreased cognitive workload.
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| 7. |
- Ferrari, Fabiano C., et al.
(författare)
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On transforming model-based tests into code : A systematic literature review
- 2023
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Ingår i: Software testing, verification & reliability. - : John Wiley & Sons. - 0960-0833 .- 1099-1689. ; 33:8
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Forskningsöversikt (refereegranskat)abstract
- Model-based test design is increasingly being applied in practice and studied in research. Model-based testing (MBT) exploits abstract models of the software behaviour to generate abstract tests, which are then transformed into concrete tests ready to run on the code. Given that abstract tests are designed to cover models but are run on code (after transformation), the effectiveness of MBT is dependent on whether model coverage also ensures coverage of key functional code. In this article, we investigate how MBT approaches generate tests from model specifications and how the coverage of tests designed strictly based on the model translates to code coverage. We used snowballing to conduct a systematic literature review. We started with three primary studies, which we refer to as the initial seeds. At the end of our search iterations, we analysed 30 studies that helped answer our research questions. More specifically, this article characterizes how test sets generated at the model level are mapped and applied to the source code level, discusses how tests are generated from the model specifications, analyses how the test coverage of models relates to the test coverage of the code when the same test set is executed and identifies the technologies and software development tasks that are on focus in the selected studies. Finally, we identify common characteristics and limitations that impact the research and practice of MBT: (i) some studies did not fully describe how tools transform abstract tests into concrete tests, (ii) some studies overlooked the computational cost of model-based approaches and (iii) some studies found evidence that bears out a robust correlation between decision coverage at the model level and branch coverage at the code level. We also noted that most primary studies omitted essential details about the experiments.
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| 8. |
- Fogelberg, Emmie, et al.
(författare)
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Current and best practices in information presentation
- 2024
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Digitalization and automation in industry can have both positive and negative effects on social sustainability. On one hand it can be a basis for monotonous, uncreative, and even dangerous workplaces and in some cases might even result in people losing their work. On the other hand, it can be a base for ergonomically sound and inclusive work, engaging everyone in improvements. This project aims for moving the focus on positive effects for social sustainability while still staying cost efficient and effective in economic and ecologic sustainability for digitalization and automation of work instructions and training in manual operations like assembly, machine operation & setup, maintenance, and material handling. The Industry 4.0 paradigm offers radically increased opportunities for doing just that. For example, increased digitization can create efficiency improvements through shorter lead times and reduced disruptions to production. New generations of technology and software as well as information dissemination can be accelerated and the traceability of products and materials in the industrial systems can be greatly increased. Digitization also provides opportunities to increase industrial resilience to challenges coming from elsewhere, such as demographic change and climate threats. Advanced application of digitization is seen by industries and decision-makers as the most important enabler for achieving the strategic sustainability goals and Agenda2030. A crucial factor for competitiveness is the human contribution. Here too, digitalisation is radically changing the conditions. In the last 20 years, work instructions have been transformed from printed text on paper into an increasingly digital representation. As knowledge increases about how work instructions for the manufacturing industry should be designed, they are rarely designed according to user conditions. At best, this results in a missed opportunity for performance improvements and at worst, it could potentially result in quality deficiencies, efficiency deficiencies and a lower degree of inclusion of staff groups. Digitization and automation permeate both society and industry more and more and there are many different technologies on the market. These can contribute to both increased efficiency and flexibility for the industry. However, there are a lot of challenges to both implement, design, and use instructions. Studies conducted in industry 2014–2018 show that operators and assembly workers only use instructions in 20–25% of cases in the operational phase when they are perceived as inefficient (Fast-Berglund & Stahre, 2013; Mattsson et al., 2018). Of course, this also increases the risks of, for example, assembly errors by not using instructions to the extent that they should be used. The corporate culture and standards are also an important part of how instructions are created and used. Depending on the structure and condition of the company and the production unit, for example, an assembly instruction at one company may include information about the product, process, and work environment, while an assembly instruction at another company includes completely different or only parts of this information. Of course, this is a natural consequence of sometimes far-inherited corporate cultures and traditions, but experience has also shown that it is to a very large extent the nature of work that defines the type of support system needed. In line with increased automation and increasing product variation as a result of increased customisation, operators’ tasks will require more creative work than before where the aim is to enable and handle the results of individual workers' creative thoughts about improvements in their own work situation, increasing cognitive load (Taylor et al., 2020). The development of digitalisation has created new opportunities for improved communication among employees in the manufacturing industry (Oesterreich & Teuteberg, 2016). Therefore, this technological development can and should support operators cognitively (Kaasinen et al., 2020; Mattsson et al., 2016). Although many new digital technologies are being developed and are available (Romero et al., 2016), it is still difficult to implement these so that people's cognitive work is supported. This is often due to the fact that the implementation does not take place in a way that people are comfortable with (Parasuraman & Riley, 1997). In many cases, humans are expected to adapt to technology and not the other way around (Thorvald et al., 2021). To implement better support for their operators, companies should focus on identifying the information needs that exist (Haghi et al., 2018) and then visualize it in a way that is useful to operators. The central aim for the project is to demonstrate how knowledge and systematic development of cognitive support and information design can increase quality and flexibility in future production and how this can be considered in the implementation of digital work instructions. In the industrial case studies, current state-of-practice in information presentation will be investigated and analysed together with state-of-the art knowledge and technology to map successful efforts in industry, identify what it is that makes them successful, or how a particularly challenging situation can be further improved through our knowledge of cognitive work in production.
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| 9. |
- Gellerstedt, Martin, 1966-, et al.
(författare)
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Are patients willing to take a more active role? : Questionnaires to measure patients’ willingness to be empowered
- 2022
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Ingår i: Patient Education and Counseling. - : Elsevier. - 0738-3991 .- 1873-5134. ; 105:3, s. 741-749
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveOne crucial prerequisite for increased patient empowerment is the willingness among patients to take a more active role. The aim of this study was to develop questionnaires for measuring a patient’s willingness to be empowered in general and by using e-health.MethodsThe study was based on a random sample from an online panel. The 800 responders were Swedish citizens and reflected the internet-using population in Sweden regarding age, gender, income, and education. The measurement properties were evaluated according to the Rasch Measurement Theory.ResultsThe analyses showed two questionnaires with adequate fit to the basic measurement model and with high reliability (PSI 0.84 and 0.89, respectively).ConclusionWe conclude that this study generated two questionnaires with an intuitive order of items illustrating an understandable progression of willingness to be empowered in general as well as for e-health.Practice implicationsThe suggested questionnaires are valuable tools supporting the effort to tailor empowerment strategies to meet the patient’s willingness. Questionnaires will also be valuable for evaluating strategies for supporting willingness, studying factors related to willingness and potential inequalities due to e.g. varying digital literacy, and for enabling identification of patient stereotypes using cluster analyses.
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| 10. |
- Ghasemi, Rohollah, 1983-, et al.
(författare)
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Abrasion resistance of lamellar graphite iron : Interaction between microstructure and abrasive particles
- 2018
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Ingår i: Tribology International. - : Elsevier BV. - 0301-679X .- 1879-2464. ; 120, s. 465-475
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on abrasion resistance of Lamellar Graphite Iron (LGI) using microscratch test under constant and progressive load conditions. The interactions between a semi-spherical abrasive particle, cast iron matrix and graphite lamellas were physically simulated using a sphero-conical indenter. The produced scratches were analysed using LOM and SEM to scrutinise the effect of normal load on resulting scratch depth, width, frictional force, friction coefficient and deformation mechanism of matrix during scratching. Results showed a significant matrix deformation, and change both in frictional force and friction coefficient by increase of scratch load. Furthermore, it was shown how abrasive particles might produce deep scratches with severe matrix deformation which could result in graphite lamella's coverage and thereby deteriorate LGI's abrasion resistance.
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