| 1. |
- Abele, H., et al.
(författare)
-
Particle physics at the European Spallation Source
- 2023
-
Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 1023, s. 1-84
-
Forskningsöversikt (refereegranskat)abstract
- Presently under construction in Lund, Sweden, the European Spallation Source (ESS) will be the world’s brightest neutron source. As such, it has the potential for a particle physics program with a unique reach and which is complementary to that available at other facilities. This paper describes proposed particle physics activities for the ESS. These encompass the exploitation of both the neutrons and neutrinos produced at the ESS for high precision (sensitivity) measurements (searches).
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| 2. |
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| 3. |
- Aquila, Andrew, et al.
(författare)
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Time-resolved protein nanocrystallography using an X-ray free-electron laser
- 2012
-
Ingår i: Optics Express. - 1094-4087. ; 20:3, s. 2706-2716
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the use of an X-ray free electron laser synchronized with an optical pump laser to obtain X-ray diffraction snapshots from the photoactivated states of large membrane protein complexes in the form of nanocrystals flowing in a liquid jet. Light-induced changes of Photosystem I-Ferredoxin co-crystals were observed at time delays of 5 to 10 µs after excitation. The result correlates with the microsecond kinetics of electron transfer from Photosystem I to ferredoxin. The undocking process that follows the electron transfer leads to large rearrangements in the crystals that will terminally lead to the disintegration of the crystals. We describe the experimental setup and obtain the first time-resolved femtosecond serial X-ray crystallography results from an irreversible photo-chemical reaction at the Linac Coherent Light Source. This technique opens the door to time-resolved structural studies of reaction dynamics in biological systems.
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| 4. |
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| 5. |
- Bujosa Mateu, Daniel, et al.
(författare)
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The Effects of Clock Synchronization in TSN Networks with Legacy End-Stations
- 2022
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we present our ongoing work on proposing solutions to integrate legacy end-stations into Time-Sensitive Network (TSN) communication systems where the legacy end-stations are synchronized via their legacy clock synchronization protocol. To this end, we experimentally identify the effects of lacking synchronization or partial synchronization in TSN networks. In the experiments we show the effects of clock synchronization in different scenarios on jitter and clock drifts. Based on the experiments, we propose preliminary solutions to overcome the identified effects.
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| 6. |
- Djärv, Tor, 1991, et al.
(författare)
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Bayesian predictions for A=6 nuclei using eigenvector continuation emulators
- 2022
-
Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 105:1
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Tidskriftsartikel (refereegranskat)abstract
- We make ab initio predictions for the A=6 nuclear level scheme based on two- and three-nucleon interactions up to next-to-next-to-leading order in chiral effective field theory (χEFT). We utilize eigenvector continuation and Bayesian methods to quantify uncertainties stemming from the many-body method, the χEFT truncation, and the low-energy constants of the nuclear interaction. The construction and validation of emulators is made possible via the development of jupiterncsm - a new M-scheme no-core shell model code that uses on-the-fly Hamiltonian matrix construction for efficient, single-node computations up to Nmax=10 for Li6. We find a slight underbinding of He6 and Li6, although consistent with experimental data given our theoretical error bars. As a result of incorporating correlated χEFT-truncation errors we find more precise predictions (smaller error bars) for separation energies: Sd(Li6)=0.89±0.44MeV, S2n(He6)=0.20±0.60MeV, and for the beta decay Q value: Qβ-(He6)=3.71±0.65MeV. We conclude that our error bars can potentially be reduced further by extending the model space used by jupiterncsm.
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| 7. |
- Ekström, Andreas, 1980, et al.
(författare)
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Bayesian optimization in ab initio nuclear physics
- 2019
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Ingår i: Journal of Physics G-Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 46:9
-
Tidskriftsartikel (refereegranskat)abstract
- Theoretical models of the strong nuclear interaction contain unknown coupling constants (parameters) that must be determined using a pool of calibration data. In cases where the models are complex, leading to time consuming calculations, it is particularly challenging to systematically search the corresponding parameter domain for the best fit to the data. In this paper, we explore the prospect of applying Bayesian optimization to constrain the coupling constants in chiral effective field theory descriptions of the nuclear interaction. We find that Bayesian optimization performs rather well with low-dimensional parameter domains and foresee that it can be particularly useful for optimization of a smaller set of coupling constants. A specific example could be the determination of leading three-nucleon forces using data from finite nuclei or three-nucleon scattering experiments.
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| 8. |
- Ekström, Maria, 1988, et al.
(författare)
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Towards phonon routing: controlling propagating acoustic waves in the quantum regime
- 2019
-
Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 21:12
-
Tidskriftsartikel (refereegranskat)abstract
- We explore routing of propagating phonons in analogy with previous experiments on photons. Surface acoustic waves (SAWs) in the microwave regime are scattered by a superconducting transmon qubit. The transmon can be tuned on or off resonance with the incident SAW field using an external magnetic field or the Autler-Townes effect, and thus the reflection and transmission of the SAW field can be controlled in time. We observe 80% extinction in the transmission of the low power continuous signal and a 40 ns rise time of the router. The slow propagation speed of SAWs on solid surfaces allows for in-flight manipulations of the propagating phonons. The ability to route short, 100 ns, pulses enables new functionality, for instance to catch an acoustic phonon between two qubits and then release it in a controlled direction.
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| 9. |
- Elfsberg, Jenny, 1973-, et al.
(författare)
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Guiding Global Innovation Teams on their Exploration Journey : Learning from Aspiring Engineering Students
- 2024
-
Ingår i: International Journal of Engineering Education. - : Tempus Publications. - 0949-149X. ; 40:3, s. 472-490
-
Tidskriftsartikel (refereegranskat)abstract
- This research investigates globally dispersed innovation teams involved in explorative projects within an engineering graduate course employing problem-based learning. Utilizing insights from a longitudinal study, the objective is to identify how to enhance both individual learning and team performance, thereby increasing the likelihood of a successful outcome. Initial observations revealed common patterns in learning experiences among the top-performing teams, prompting further investigation into how supporting cohorts might positively influence both team performance and students’ learning experiences throughout the course. In addition to advancing comprehension of innovation team performance, the study introduces two lightweight tools designed as shared visual representations of the team’s exploration journey. These tools can assist supporting cohorts in guiding teams effectively. This research augments the existing body of knowledge surrounding the achievement of breakthrough innovations. It provides understanding about how to facilitate team performance and individual learning within globally dispersed innovation teams undertaking explorative projects. The proposed lightweight tools offer practical solutions to enhance the supporting cohort’s ability to guide and impact team performance and individual learning experiences. This study holds implications for academia and industry, particularly organizations reliant on radical innovation for competitiveness and future-proving. Lastly, the study’s findings could inform the design and delivery of future problem-oriented, project-organized learning-based courses in engineering education.
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| 10. |
- Elfsberg, Jenny, 1973-, et al.
(författare)
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How Covid-19 Enabled a Global Student Design Team to Achieve Breakthrough Innovation
- 2021
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Ingår i: Proceedings of the Design Society 2021. - : Cambridge University Press. ; , s. 1705-1714
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Konferensbidrag (refereegranskat)abstract
- This is a qualitative single case study of a geographically distributed student team that experienced a quite different graduate course, compared to previous year's. This was due to the restrictions placed upon them following coronavirus lockdowns. With already ongoing research, and continuous development of the course, the authors had documented individual reflections and identified patterns and behaviours that seemingly determined the quality of the end result, as well as the students expectations and experiences. Semi-structured interviews, surveys and the author's individual reflection notes were already in place as part of the larger research scope and when the student team during the covid-19 year showed unexpected performance and results, the authors decided to pause the larger research scope and focus on this unique single case and capture those learnings. Not knowing how the Covid-19 situation evolves and leaning on insights from previous years, as well as this unique year, the aim with this paper is to describe the unique Covid-19 year amd share knowledge that can help improve and evolve the development of this longlived collaborative graduate student course, and other similar distributed team contexts.
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| 11. |
- Elfsberg, Jenny, 1973-
(författare)
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Innovation Engineering in Practice : Bridging Exploration and Exploitation in Large Manufacturing Incumbents
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis discusses how large manufacturing incumbent companies potentially can ensure their longevity and future-proof themselves by infusing ambidexterity throughout their organizations. Ambidextrous companies are equipped to achieve success in both current and future business environments, providing valued solutions to customers today and in the future. While these companies often excel at making incremental improvements to existing products, business, and operational models, they lack the skill set necessary for exploring new ways of creating value for customers, and commonly fail to bring promising breakthrough innovations from proven concept to revenue generation. To address these challenges, this thesis proposes a methodology consisting of four foundational principles for strengthening the innovation capacity of large manufacturing incumbents. The term "innovation engineering" is introduced and described to distinctly differentiate exploration-oriented work from exploitation-oriented work and demystify the exploration process and skills. The thesis also presents the concept of "intentional PSS design" as an approach to incorporate future aspirations and current capabilities into an evolutionary design process, connecting current limitations with future anticipated possibilities.The thesis proposes tools for leaders and coaches to support innovation engineering teams in their exploration journeys and bridge the gap between exploration and exploitation. The overall aim of the research is to future-proof large manufacturing incumbents by providing understanding about common challenges and possibilities, a framework for strengthened innovation capacity, incorporating the innovation engineering skills as core competencies, and the innovation engineering process as equally important to and diametrically different from the exploitation process.The research aims to increase awareness and knowledge about innovation engineering and enable infused ambidexterity so that large manufacturing incumbents can find their ways to adapt to a changing environment and reinvention of their ways to meet customer needs. The thesis also proposes ways to bridge between exploration and exploitation to enable a company-wide transition from a product-selling to problem-solving enterprise. By doing so, large manufacturing companies might prolong their lifespan and contribute solving
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| 12. |
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| 13. |
- Elfsberg, Jenny, 1973-, et al.
(författare)
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Lost in translation between explore and exploit : From selling products to solving problems in large manufacturing incumbents
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- As large manufacturing incumbents are adopting digital technologies and shifting their business models from selling products to solving problems, through PSS (product-service-system) solutions, their development processes need to shift as well. Organizational ambidexterity, the ability to both explore new opportunities and exploit existing customer offerings, is considered to be crucial to companies’ current and future success. In this study it is observed that a gap between exploration and exploitation work streams lead to promising conceptual PSS solutions never reaching a revenue generating stage. This is because product-centricity along with exploitation-optimized processes and mindsets are not equipped to carry the integrated solutions further, from proven concept to market ready solution. This article summarizes a multiple case study, where systematic innovation engineering work has resulted in promising conceptual PSS solutions never reaching market launch. In addition to the in-depth case studies, leaders of exploration-oriented teams in manufacturing incumbents shared their insights which confirmed that the problem is common across companies and industries, and several roadblocks are general. One of the authors has been responsible for a successful shift from a product-centric to an integrated solution-oriented organization and contributed insights from that experience to this study. The authors suggest that the gap between explore and exploit, and the shift from product-centric to PSS-oriented can be managed through an approach where ambidexterity is infused into the entire organization and exploration is demystified, enabling a transparent and concerted shift.
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| 14. |
- Elfsberg, Jenny, 1973-, et al.
(författare)
-
Unlocking the full value of a corporate innovation hub
- 2020
-
Ingår i: <em>The Proceedings of ISPIM Connects Global 2020: Celebrating the World of Innovation</em>. ISPIM.. - : LUT Scientific and Expertise Publications. - 9789523355668
-
Konferensbidrag (refereegranskat)abstract
- This paper covers research about how Corporate Innovation Hubs, CIHs, in Silicon Valley are managed and supported by their corporatemotherships and how their likeliness of success can be increased by consciousand proactive management and support. To embrace the cultural difference as a competitive advantage and learning experience is important. Clear intentions,expectations, team constellation, reporting level and finding the right individualas head of the CIH are identified as crucial factors to consider.
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| 15. |
- Frank, Martin, 1984-, et al.
(författare)
-
Towards autonomous construction equipment : supporting on-site collaboration between automatons and humans
- 2019
-
Ingår i: International Journal of Product Development. - : InderScience Publishers. - 1477-9056 .- 1741-8178. ; 23:4, s. 292-308
-
Tidskriftsartikel (refereegranskat)abstract
- To support the application of automated machines andcollaborative robots in unstructured environments like in the mining,agriculture and construction sector the needs of the human co-workershould be investigated to ensure a safe and productive collaboration.The empirical study presented includes the prototyping of a solution forhuman-machine communication, which has been supported by a designthinking approach. An understanding of the human needs had beencreated through jobsite observations and semi-structured interviewswith human workforces working in close proximity to heavy mobileequipment. The results shows that trust and communication have a bigimpact on the jobsite collaboration.
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| 16. |
- Johansson, Andreas, 1980, et al.
(författare)
-
DYNAMICS OF IN-FURNACE PROCESSES IN A CFB BOILER
- 2005
-
Ingår i: Proceedings of the 8th International Conference on Circulating Fluidized Beds. - 7506274426 ; , s. 159-166
-
Konferensbidrag (refereegranskat)abstract
- With the aim of understanding the dynamics of combustion, this work examines simultaneous fluctuations in fluid dynamic parameters and gas composition in a CFB furnace operated with coal as a fuel. Fluid dynamic parameters are pressure and air flow to the furnace. Gas composition was obtained by a zirconia-cell probe and a gas suction probe connected to a mass spectrometer having a high time resolution (10 Hz). The fluctuations of interest are around 1 Hz and below 0.3 Hz. The fluctuations below 0.3 Hz, which have not been investigated previously, are found to originate from irregularities in the fuel feed. These irregularities give rise to periods of reducing conditions because high inputs of fuel yield an increased pressure in the furnace and a decreased air feed to the furnace, which then occurs concurrent with the release of a high amount of volatiles. There is also a correlation between reducing conditions and the concentration of hydrocarbons.
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| 17. |
- Johansson, Andreas, 1980-
(författare)
-
Pragmatic Muslim Politics : The case of Sri Lanka Muslim Congress
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation investigates the use of religious terms and symbols in politics. More specifically, it investigates Muslim politics. Its aim is to analyze the role of religious terms and symbols within a non-fundamentalist political party, namely the Sri Lanka Muslim Congress (SLMC), a Muslim political party that has been part of the democratic process in Sri Lanka since the 1980s. I thereby hope to broaden the range of research concerning political parties founded on religious ideologies. The empirical focus of the dissertation is on the official documents of the SLMC, such as internal documents to members, online publications from their official website and social media. The empirical data also includes parliamentary speeches made by the late leader M.H.M. Ashraff during the years from 1989 to 1992 and parliamentary speeches made by the current leader Rauff Hakkem during the years from 2006 to 2011. I have also conducted interviews with 33 leading members of the party on three different occasions. In 2006, 2011 and 2013 I visited Sri Lanka and had Colombo as my base.This thesis also contains an introduction to the history of Muslims in Sri Lanka and thereafter the structure of this thesis follows the different empirical data that I have collected. The first of my empirical chapters focuses on official documents written by the SLMC. The second presents and examines interviews with leading members of the SLMC. The third and fourth empirical chapters concern the parliamentary speeches of the two party leaders mentioned above, M.H.M. Ashraff (1989–1992) and Rauff Hakeem (2006–2011). The final chapter discusses the conclusions drawn from the empirical chapters in relation to the theoretical framework presented in Chapter 2.In sum, “Pragmatic Muslim politics” can be seen as the complete opposite of a politics that is ideology driven and utopian. This fits well with what has been observed in the case of the SLMC. The main use of references to Islam as a religious tradition in the party has been to delimitate Muslims as a specific group in a political situation in post-colonial Sri Lanka. While there have been some initial attempts made, particularly during the 1990s, to put forward specific “Islamic” solutions to social problems, with direct references made to the scriptures particularly in the field of economics, few if any such attempts can be seen today.
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| 18. |
- Johansson, Andreas, 1980, et al.
(författare)
-
Solods back-mixing in CFB furnaces
- 2005
-
Ingår i: Proceedings of the 8th International Conference on Circulating Fluidized beds. ; 8, s. 151-158
-
Konferensbidrag (refereegranskat)
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| 19. |
- Johansson, Andreas, 1980-
(författare)
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Yakuza Tattoo
- 2017
-
Bok (populärvet., debatt m.m.)
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| 20. |
- Johansson, Christoffer, et al.
(författare)
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Järnvägsbroar på Botniabanan : Dynamiska kontroller för framtida höghastighetståg - Steg 1
- 2013
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I föreliggande rapport har inventering och dynamiska kontroller utförts på 76 järnvägsbroar längs Botniabanan. Samtliga broar är byggda under perioden 1999 – 2009 och dimensionerade statiskt för tåglast BV2000. Broarna kan indelas i tre grupper; balk- och plattbroar, plattrambroar och samverkansbroar.Baserat på förenklade dynamiska analyser erhålls ett överskridande av den vertikala accelerationen för 75 % av alla plattrambroar och 40 % av alla balk- och plattbroar. Överskridande erhålls även för 4 av 9 samverkansbroar. Av totalt 76 analyserade broar motsvarar detta 41 broar som inte uppfyller kravet på sth 250 km/h. En sänkning till sth 200 km/h ger att 26 broar inte klarar de dynamiska kraven. Fyra broar har en nominell kritisk hastighet under 120 km/h.För plattrambroarna är accelerationsnivån i hög grad beroende på grundläggningsförhållandena. Enligt tidigare BV Bro medräknades endast frekvenser upp till 30 Hz, vilket i kombination med antagande om oeftergivliga stöd ofta resulterade i att dynamiska kontroller inte utfördes för plattrambroar. Eftergivlighet hos grundläggningen resulterar i vertikala stelkroppsmoder som i kombination med medsvängande massa av angränsande fyllning ger låga egenfrekvenser och därmed låga resonanshastigheter.För balkbroar beräknas mycket höga accelerationsnivåer då dessa är utformade med ändskärmar. Orsaken är att tåglasten inducerar en stötbelastning då den passerar änden på ändskärmen. Detta ger höga accelerationsnivåer även i angränsande spann, även utanför ett resonanstillstånd. Plattbroar ger ofta högre accelerationsnivåer jämfört med motsvarande balkbroar, beroende på att en lägre böjstyvhet ger lägre resonanshastighet. Detta förvärras kraftigt för plattbroar utformade med ändskärmar, vilket identifierats för t.ex. bro över Sidensjövägen.För samverkansbroarna beror de höga accelerationsnivåerna på en kombination av låg böjstyvhet och låg massa, vilket ger en låg resonanshastighet och hög accelerationsnivå. Problemet är störst för två fritt upplagda broar, Banafjälsån och Bryngeån.Förslag på fortsatta utredningar i syfte att påvisa att fler broar klarar de dynamiska kraven inkluderar mer avancerade analysmetoder i kombination med fältmätningar och kontrollerad excitering. Det bedöms i nuläget finnas stor potential att påvisa lägre accelerationsnivåer baserat på mindre konservativa antaganden om t.ex. dämpning och samverkan mellan bro och omgivande fyllning.
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| 21. |
- Johansson, Christian, 1980-
(författare)
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Knowledge engineering in the virtual enterprise : exploring a maturity-based decision support
- 2007
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In product development, lead-time reduction, cost reduction, and quality improvement are issues that companies want to improve on to increase competitiveness. One recent approach to reach this - particularly in the aerospace industry where the complexity of product offers is steadily increasing - is to manage risk by forming virtual enterprises. A virtual enterprise is a network of partner companies that join on equal terms when an opportunity arises to develop a product offer, e.g. a jet engine offer, in a more agile manner than if any of the partners would realise it by themselves. They therefore team up to share risk, investment and resources - to in return also share revenue and profit. A driver for the formation of the virtual enterprise is the ability to effectively utilise partner knowledge assets. However, when sharing and managing knowledge effectively across the virtual enterprise, current practices have yet to evolve to meet the needs of knowledge workers, who may come from different aerospace companies, have different roles, belong to different disciplines and that may also be situated in geographically dispersed locations.Improving product development includes allowing developers from all disciplines to know - as early as possible in the product development process - more about the customer needs, the desired product properties, and the downstream impact of the decisions they choose to make throughout the process. Knowing about the impact in downstream phases would allow for significant time and cost savings due to the avoidance of unnecessary and expensive rework that would otherwise occur much further on in the product's life cycle.Among other things, a virtual enterprise can start organising and mapping the knowledge assets available in their teams, and information overload can be managed by assuring that the right knowledge ends up with the right person, to mention but a few things that can facilitate the everyday work of engineers and their colleagues. When working in a product development project, the virtual enterprise needs to assess the quality of the created knowledge as early as possible to devise the correct actions early. In this thesis, a Gated Maturity Assessment technique including the concept of knowledge maturity has been developed as an example of an improved stage-gate decision-making process. With this approach development teams are able to assess the knowledge maturity level in the content and rationale that is put forward as a basis for a decision - as opposed to only assessing the raw data of the results (i.e. thrust, weight, fuel burn, etc.). Knowledge maturity is used to support decision makers when in the process of assessing a decision base to make a decision whether to go ahead, abort the process, or order rework to be done. Naturally, if the decision base is poor, a decision to go ahead should probably not be taken, as the consequences might be negative. In assessing maturity, decision makers can determine at decision points if the knowledge base is good enough to move forward to the next step in the jet engine component design, if there is need for rework, and what specific areas need to be improved. Decision makers can divert and focus resources to areas of importance due to, for instance, too low maturity levels.Knowledge maturity is a way to - using a criteria scale that prescribes the knowledge needed at each level - help development teams assess and visualise how well they know what they know, and subsequently, what they need to know. This thesis explores the feasibility of using knowledge maturity as a way of supporting knowledge engineering in the context of a development process in aeronautics.
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| 22. |
- Johansson, Christian, 1980-
(författare)
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Knowledge maturity as decision support in stage-gate product development : a case from the aerospace industry
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In today’s fast-paced industry where fight for market share is fierce and reaching the market ahead of competition imperative, product development is a target for lead-time reductions. In this context, in product development in stage-gate processes, decisions need to be made even though knowledge and information are scarce and flawed. The challenge is how to support the decisions that are made in light of uncertainty and ambiguity. The thesis moves from analysing the role of the stage-gate process within the aerospace industry. The stage-gate process was more than a decision making mechanism, and instead a mechanism that facilitated communication, discussion and knowledge sharing between team members, as well as supported knowledge creation and shaping of the boundaries between people’s different perceptions of the knowledge base. However, the communicative and negotiative function of the stage-gate was highly dependent on the ability of the participating individuals to reflect on the status and quality of the available knowledge assets used throughout the process. To make this reflective activity an explicit part of the stage-gate practice, this thesis proposes the application of a knowledge maturity concept at the gates to raise the decision makers’ awareness of the status of the knowledge assets handled at the decision point. The knowledge maturity concept considers three basic dimensions: input, method/tool and experience/expertise in assessing the knowledge base maturity. The scale is intended to act as a boundary object, facilitating the knowledge creation process by highlighting the current status of the knowledge base and making stakeholders aware of the nature of the project’s uncertainties and ambiguities. In the knowledge maturity concept, its purpose is to support design teams at the gates in taking appropriate action, mitigating risk and focusing their efforts on improving the knowledge assets where it is needed most, regarding the situation at hand and, finally, to make more confident decisions.The thesis was developed within the EU FP6 VIVACE (Value Improvement through a Virtual Aeronautical Collaborative Enterprise) and EU FP7 CRESCENDO (Collaborative and Robust Engineering using Simulation Capability Enabling Next Design Optimisation) projects, and within the Faste Laboratory, a VINNOVA Excellence Centre involving partners from the Swedish manufacturing industry.
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| 23. |
- Johansson, Christoffer, et al.
(författare)
-
Probabilistic Dynamic Analysis of Existing Railway Bridges for High-Speed Traffic
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The Swedish government is considering upgrading the train speed along three railway lines in the Southern part of Sweden from 200 km/h to 250 km/h. According to the current design code, this requires that the bridges be examined with dynamic simulations to avoid excessive vibrations. This paper employs a method that can be used at an early stage to estimate the expected cost of upgrading a bridge network. The results revealed that 70% of the plate/beam bridges, 64% of the closed slab-frame bridges, and 41% of the open slab-frame bridges are expected to not fulfil the requirement on the maximum bridge deck acceleration for ballasted tracks.
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| 24. |
- Johansson, Christian, 1980-, et al.
(författare)
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Virtual Meeting Interoperability : Discussing the need of support for heterogeneous meeting environments
- 2006
-
Ingår i: Proceedings of the Fourth IASTED International Conference on Knowledge Sharing and Collaborative Engineering. - 0889866090 - 0889866112 ; , s. 92-97
-
Konferensbidrag (refereegranskat)abstract
- With more projects in today’s industry being global it is important to support the people collaborating in these projects. Travel is expensive and time consuming and is not viable in the long run. Although some travel is necessary it is important for people to meet virtually instead. In many cases it is difficult for companies to collaborate because they do not use the same tools for these virtual meetings. Due to restrictions with IT security it is also difficult and expensive to implement every new tool their partner companies use. One solution could be a portal that facilitates connecting users with different virtual meeting tools. Using Web Services to bridge the different protocols it would be possible to connect two software packages that are using different standards for virtual meetings. With a tool as this it would be possible for chosen companies to collaborate closely online although they have incompatible software packages. Companies can select their solutions on the basis of their needs and do not have to implement a new solution or modify their existing setup to accommodate new partner needs. Finally, people would only need to learn the one tool which is available in their own company.
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| 25. |
- Johansson, Gunnar, 1981-, et al.
(författare)
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Distributed Ray Tracing in an Open Source Environment (Work in Progress)
- 2006
-
Konferensbidrag (refereegranskat)abstract
- We present work in progress on concurrent ray tracing with distributed computers using ``off-the-shelf'' open source software. While there exists numerous open source ray tracers, very few offer support for state-of-the-art concurrent computing. However, it is a well known fact that ray tracing is computationally intensive and yet prevails as the preferred algorithm for photorealistic rendering. Thus, the current work is driven by a desire for a simple programming strategy (or recipe) that allows pre-existing ray tracing code to be parallelized on a heterogenous cluster of available office computers - strictly using open source components. Simplicity, stability, efficiency and modularity are the driving forces for this engineering project, and as such we do not claim any novel research contributions. However, we stress that this project grew out of a real-world need for a render cluster in our research group, and consequently our solutions have a significant practical value. In fact some of our results show a close to optimal speedup when considering the relative performances of each node. In this systems paper we aim at sharing these solutions and experiences with other members of the graphics community.
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| 26. |
- Johansson, Linda C, 1983, et al.
(författare)
-
Lipidic phase membrane protein serial femtosecond crystallography.
- 2012
-
Ingår i: Nature methods. - : Springer Science and Business Media LLC. - 1548-7105 .- 1548-7091. ; 9:3, s. 263-265
-
Tidskriftsartikel (refereegranskat)abstract
- X-ray free electron laser (X-FEL)-based serial femtosecond crystallography is an emerging method with potential to rapidly advance the challenging field of membrane protein structural biology. Here we recorded interpretable diffraction data from micrometer-sized lipidic sponge phase crystals of the Blastochloris viridis photosynthetic reaction center delivered into an X-FEL beam using a sponge phase micro-jet.
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| 27. |
- Johansson, Markus, 1978, et al.
(författare)
-
Comparison between Two Phase Retrieval Methods for Electromagnetic Source Modeling
- 2011
-
Ingår i: Progress in Electromagnetics Research B. - 1937-6472. ; 30, s. 239-253
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Tidskriftsartikel (refereegranskat)abstract
- Phase-retrieval from measured phaseless field data is of interest for various applications including electromagnetic dosimetry, electromagnetic compatibility investigations, near-field to far-field transformations and antenna diagnostics. In this study two phaseretrieval methods are compared. The first method, the adjoint field method, employs a gradient-based optimization algorithm based on the adjoint fields. The second method, the phase angle gradient method, uses an optimization algorithm based on the phase angle gradients of a functional. The methods are tested with numerical test cases and the phase angle gradient method is found to retrieve the phase with the best accuracy. Moreover it gives results that agree well with correct phase.
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| 28. |
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| 29. |
- Johansson, Markus, 1978, et al.
(författare)
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Electromagnetic Source Modeling using Phase Retrieval Methods
- 2011
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Ingår i: 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011, Istanbul, 13-20 August 2011. - 9781424451173 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- Modeling of the field distributions from electromagnetic sources is of interest for various applications for example electromagnetic compatibility investigations, near-field to far-field transformations, antenna diagnostics and electromagnetic dosimetry. In order to determine whether exposure safety guidelines, such as the EU directive 2004/40/EC, are complied with, source modeling methods are important. Two methods for determining the total field, including phase information, when only field amplitudes have been measured on a set of planes in front of an electromagnetic source have been developed. The first method, the adjoint field method, is a gradient based optimization algorithm based on the adjoint fields. The second method, the phase angle gradient method, employs an optimization algorithm based on the phase angle gradients of a functional. Promising results have been obtained both for numerical test cases and for measured field.
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| 30. |
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| 31. |
- Johansson, Mona, et al.
(författare)
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Platelet adhesion in type 2 diabetes : impact of plasma albumin and mean platelet volume.
- 2021
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Ingår i: Thrombosis Journal. - : BioMed Central (BMC). - 1477-9560. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Altered mean platelet volume (MPV) and plasma albumin has been reported in type 2 diabetes (T2D). MPV is suggested to predict cardiovascular risk but there is a lack of evidence for associations between MPV and platelet adhesion. Plasma albumin and magnesium are other factors reported to influence thrombotic risk. The objectives of this study were to assess the association between platelet adhesion and plasma factors with a potential role to affect platelet activation.METHODS: Blood was collected from 60 T2D patients and 60 healthy controls. Platelet adhesion to different protein surfaces induced by various soluble activators were measured in microplates. MPV, albumin and magnesium were analysed together with additional routine tests.RESULTS: Despite normal levels, plasma albumin significantly correlated with adhesion of T2D platelets but not with controls. There was a significant association between MPV and platelet adhesion in both groups, but association was smaller in T2D. Levels of glucose, HbA1c or magnesium did not correlate with platelet adhesion.CONCLUSIONS: Plasma albumin was associated with platelet adhesion in T2D suggesting that albumin may be a factor to consider upon cardiovascular risk assessment. MPV was more associated with the level of platelet adhesion in healthy individuals than in well-controlled T2D patients.
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| 32. |
- Johnsson, Filip, 1960, et al.
(författare)
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In-furnace processes in a 235 MWe CFB boiler
- 2002
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Ingår i: Proc. of the 7th International Conference on Circulating Fluidized Beds. - 9780920804988 ; , s. 607-614
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Konferensbidrag (refereegranskat)abstract
- In an experimental project funded by the 5th Framework Programme of the European Community (EC), different measurement techniques are used to analyze in-furnace processes in a 235 MWe Circulating Fluidized Bed (CFB) boiler in Turow, Poland. The purpose of the project is to assess the insufficiently known features of large-scale CFB boilers. The furnace of the boiler has a cross-section of 21 x 10 meters and a height of 43 meters. The boiler is operated on a local brown coal. Steady state, as well as dynamic conditions, are studied. The project is unique in two respects: Firstly, several measurement ports are provided in the large CFB furnace for in-situ measurements in various locations on the furnace. Secondly, a number of measurement techniques are employed. These facilitate studies of hydrodynamic processes as well as local variations in gas components (such as O2, CO, THC) and solids materials. The paper describes the measurement techniques and provides examples of the first (hydrodynamic) results obtained by the in-situ measurements.
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| 33. |
- Larsson, Ingrid, 1968-, et al.
(författare)
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Sleep interventions for children with attention deficit hyperactivity disorder (ADHD) : A systematic literature review
- 2023
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Ingår i: Sleep Medicine. - Amsterdam : Elsevier. - 1389-9457 .- 1878-5506. ; 102, s. 64-75
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Forskningsöversikt (refereegranskat)abstract
- Objective/background: Healthy sleep is particularly important for children with attention deficit hyperactivity disorder (ADHD), as sleep disturbances might aggravate disease symptoms. This review aims to synthesize and report evidence on the effectiveness of sleep interventions in increasing sleep, quality of life (QoL), and ADHD symptoms among children with ADHD. Patients/methods: The systematic literature review follows the Cochrane Collaboration methodology recommendations for literature reviews. Four databases were used based on the population, intervention, control and outcome (PICO) framework. Controlled trials with minimum 20 children in each group, aged 6–18, and published from 2005 and onwards were included. Results from the studies were reported in forest plots and three of the seven review outcomes were synthesized in meta-analyses. Results: The search identified 7710 records; of which 4808 abstracts were screened. After fulltext-screening of 99 papers, eight papers from five studies were included. The studies included behavioral sleep interventions and pharmacological interventions using melatonin and eszopiclone. For six of the seven outcomes, the effect sizes were small to moderate and the certainty of the evidence was low. For one outcome, sleep disturbances, the effect size was a moderate −0.49 standardized mean differences (95% confidence interval −0.65;-0.33), with a moderate certainty of evidence for the behavioral interventions for children aged 5–13 years with ADHD. Conclusions: This review identified few and heterogeneous studies. A moderate certainty of evidence for a moderate effect size was only obtained for sleep disturbances from the behavioral interventions. A low certainty of the evidence for a moderate effect size was found for the total sleep time from the pharmacological intervention using melatonin and one behavioral intervention, which indicates that these sleep interventions impact sleep quantity and quality among children with ADHD. © 2022 The Authors
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| 34. |
- Liu, Chengxi, 1987-, et al.
(författare)
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Skattning av ruttvalsmodell för cykel för svenska förhållanden (RUCY)
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Avgörande för ökat hållbart resande är tillgängligheten till hållbara färdmedel. Planering för cykeltrafik blir därför ett allt viktigare område. Därmed behöver våra transportmodeller förbättras i hur de modellerar cykelresor och specifikt hur cyklisters ruttval bör modelleras. Under 2019 har rapporten ”Behovsanalys för cykeltrafikmodeller” levererats till Trafikverket och Sveriges Kommuner och Regioner. Rapporten sammanfattar behov av att vidareutveckla makroskopiska trafikmodeller bland annat för att utvärdera effekter av cykelinvesteringar/åtgärder. I projektet RUCY adresserar vi denna fråga. Många investeringsåtgärder handlar om att bredda befintliga cykelbanor vilket inte kan utvärderas med det befintliga samhällsekonomiska analysverktyget. Även internationellt har nästan inga studier fångat upp hur cykelbanans bredd har påverkat ruttvalet. Det finns därmed ett värde i att öka kunskapsmängden inom området och jämföra resultat mellan olika länder/städer.RUCY använder GPS-data från ca 13 000 cykelresor från projektet ”Bike data – Crowd sourced Big Data för cykling” för att skatta en ruttvalsmodell för cykel för Göteborg. En modell baserad på HIdden-Markovs kartmatchningsalgoritm används för att identifiera rutter utifrån GPS-spår. Möjliga alternativa rutter genereras via upprepade ruttsökningsmetoder samt observerade rutter med samma start- och målpunkt. En Path-size-logit-modell har skattats med relativa effekter för exempelvis cykelbana med olika breddkategorier, belysning och lutning.Resultaten visar att osäkerhet i kartmatchning, som inte har fått uppmärksamhet i de flesta tidigare studierna, har en stor påverkan på modellskattningsresultaten. Studien lyckas fånga resenärernas skillnad i upplevd resuppoffring mellan cykelbana med bredd mindre än 2 meter och de med bredd större än 2 meter. Studien fångar också effekter av lutning, korsningsfördröjning, belysning samt typ av beläggning. Effekterna jämförs med internationella studier. Fångade effekter av bredd av cykelbana möjliggör utvärdering av infrastrukturinvesteringar som breddar befintliga cykelbanor. Dock noterar vi att fler känslighetsanalyser med avseende på effekter av cykelbanans bredd behövs. Studien illustrerar hur resultat av ruttvalsmodeller kan integreras i en transportmodell som möjliggör utvärdering av relevanta policyåtgärder för cykel.
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| 35. |
- Liu, Chengxi, 1987-, et al.
(författare)
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Utveckling av cykelruttvalmodell för Göteborg
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 487-487
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Avgörande för ökat hållbart resande är tillgängligheten till hållbara färdmedel. Detta forskningsprojekt syftar till att utveckla en modell för cyklisters ruttval. Studien syftar till att undersöka effekter av policyrelevanta variabler som inte är undersökta i tidigare studier av denna typ, t ex breddning av befintlig cykelbana, vilket är en av de vanligaste cykelinfrastrukturåtgärderna i Sverige. Vidare i studien hittade vi en ”parallella länkar problem” och därför studien också undersöker vilken utsträckning en kombination av brusiga GPS-data och högupplösta nätverk leder till osäkerhet i kartmatchning och hur detta påverkar skattningsresultaten när det gäller ruttvalsmodell för cykel. Vi använder GPS-data med ca 13 000 cykelresor från projektet ”Bike data - Crowd sourced Big Data för cykling” för att skatta en ruttvalsmodell för cykel för Göteborg. En Hidden-Markov-modell-baserad kart-matchningsalgoritm används för att identifiera rutter utifrån GPS-spår. Möjliga alternativa rutter genereras via upprepade ruttsökningsmetoder samt observerade rutter med samma start- och målpunkt. En Path-size-logit-modell skattas med relativa effekter för exempelvis cykelbana, belysning och lutning. Resultaten visar att osäkerhet i kart-matchning, som inte har fått uppmärksamhet i de flesta tidigare studierna, har en stor påverkan på modellskattningsresultat. Därför bör det undersökas om GPS-data är med låg precision. Studien lyckas fånga resenärernas skillnad i upplevd resuppoffring mellan cykelbana med bredd <=2 meter och de med bredd > 2 meter. Studien fångar också effekter av lutning, korsningsfördröjning, belysning samt typ av beläggning. Effekterna jämförs med internationella studier. Skattade ruttvalsparametrarna är centrala för att transportmodellen ska kunna uppskatta cykeltrafikflöde på nätverksnivå korrekt. Fångade effekter av bredd av cykelbana möjliggör utvärdering av infrastrukturinvesteringar som breddar befintliga cykelbana, dvs man kan beräkna cykelflödesskillnaden före-efter en breddningsinvestering. Studien illustrerar hur resultat av ruttvalsmodell tillsammans med en transportmodell kan utvärdera relevanta policyåtgärder för cykel.
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| 36. |
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| 37. |
- Nord, Lovisa, 1980, et al.
(författare)
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Near Field Modeling of Complex Sources
- 2006
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Ingår i: Bioelectromagnetics Society (BEMS) 28th Annual Meeting, June 11-15, 2006, Cancun, Mexico.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 38. |
- Ruvald, Ryan, et al.
(författare)
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EVALUATING PROTOTYPING SUPPORT IN EARLY TRANSFORMATIVE PSS DESIGN
- 2021
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Ingår i: Proceedings of Design Society 2021. - : Cambridge University Press. ; , s. 1411-1420
-
Konferensbidrag (refereegranskat)abstract
- Prototypes are an established tool for rapidly increasing learning, communication and decision making rationale for design projects. The proven success has spawned a litany of approaches and methods for building and planning the efficient planning and construction of prototypes. Translating these methods into simple usable tools to assist novice designers has generated broadly applicable canvases to support prototyping across the design process. Product Service System design has similarly introduced prototyping methods and tools into the process. Presently there is a lack of support for generating early phase tangible prototypes for functional PSS design aimed at more radically innovative solutions instead of currently dominant traditional products with traditional add-on services. This work explores the viability of utilizing existing prototyping support tools in the context of early PSS design through workshops with student designers and practitioners. The data from these workshops illuminates the alignments and misalignment gaps presented as guidelines to enable better support for early PSS designers.
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| 39. |
- Ruvald, Ryan
(författare)
-
Innovation in a Changing World : Exploring PSS Design through Prototyping
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Customers across all sectors have increasing expectations (e.g. value, efficiency, availability, quality, etc.) and expanding needs which traditional business models fail to address simultaneously and stand-alone products cannot be expected to solve. To expand the value provided to customers, manufacturers have begun adding services to their products through servitization. Similarly, service providers have begun adding products to expand their ability to capture market capacity. The end coupled product and service solutions have been classified as Product Service System (PSS) solutions. The challenge lies in defaulting to existing products or services as the starting point since these solutions can carry forward inefficiencies or limitations of legacy solutions. There is a recent proposal to integrate PSS design into a single process, rather than using separate design flows for products, services, and systems. This approach involves intentionally designing all elements together at the same time. Ideally, this approach will allow the most efficient existing and new products or services to be combined into a solution which produces exponentially more value than the sum of the individual elements. Realigning all components of a PSS from inception towards a function provides an opportunity to escape current product limitations and explore new solutions with potentially higher value. This approach becomes an increasingly wicked challenge of having a transformative view of the future solution scenario at the conceptual start of the design process while navigating the increased ambiguity brought forth due to the nature of PSS solution variability. A core tenet of the Design Thinking (DT) mindset prescribes extensive use of physical prototypes as a means to “dance with ambiguity” encouraging generative exploration in the early conceptual phases of design. This “show don’t tell” tenet of DT is incorporated in a novel way into what this research will define as "Intentional PSS design” through physical system prototypes to accomplish two primary objectives; Enabling internal consensus in a project team through rapid design space exploration and provoking Generative Design Questions from the various potential stakeholders up and down the future value chain. These prototypes enable co-creation of conceptual solutions that may not be technically possible today, but have enough impact potential to warrant deeper exploration and refinement to enable their evolution. The aim of this thesis is to explore the phenomenon of creating and utilizing physical prototypes in the conceptual phase of PSS design. The initial context and case studies are within the domain of construction equipment manufacturing. The resulting work produced a functional scale prototype of a future solution yielding valuable gains in co-creation and GDQs. Generating this prototype and understanding its impacts in the conceptual phase of the PSS design process is the phenomenon in question for the first half of the research. The second half of the research focuses on how to enable other designers to replicate the observed prototyping qualities through various experimental means delivered via workshops. The work was performed in collaboration with a construction equipment manufacturer, conducting an exploration into the impacts of shifting towards autonomous electric machinery at a demonstrator production site. The thesis first depicts how the prototyping around the ancillary impacts and solutions leads to greater engagement from stakeholders regarding the new concepts. The later portion explores two methodological attempts at generalizing the process behind the creation of the demonstrator scale site as a boundary object for early phase exploration that are previously not accessible through current practices. This leads to the testing of the method in a broader perspective to represent tangible and intangible elements in a way that facilitates concept design decisions in interdisciplinary team settings. The thesis concludes by exploring the potential of utilizing the new workshop-based processes to move from an ambiguous asipirational goal towards an uncertain transformative PSS solution concept anchored by physical representations aiding concept generation, refinement and selection.
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| 40. |
- Ruvald, Ryan, 1986-, et al.
(författare)
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PSS DESIGN INNOVATION : PROTOTYPING IN PRACTICE
- 2020
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Ingår i: Proceedings of the Design Society. - : Cambridge University Press. ; , s. 1355-1364
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Konferensbidrag (refereegranskat)abstract
- Heavy equipment manufacturers recognise an opportunity to realise customer value gains through offering new Product-Service Systems. Such transition implies a radical shift in how new systems are designed. Based on a set of interviews the paper investigates how radical PSS innovation can be enabled by the use of physical prototypes as boundary object to navigate early PSS design ambiguity. On such basis, suggestions for augmenting existing support tools are made in relation to the existing literature.
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| 41. |
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| 42. |
- Schneider, Ben, 1983, et al.
(författare)
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Observation of Broadband Entanglement in Microwave Radiation from a Single Time-Varying Boundary Condition
- 2020
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 124:14
-
Tidskriftsartikel (refereegranskat)abstract
- Entangled pairs of microwave photons are commonly produced in the narrow frequency band of a resonator, which represents a modified vacuum density of states. We generate and investigate the entanglement of a stream of photon pairs, generated in a semi-infinite broadband transmission line, terminated by a superconducting quantum interference device (SQUID). A weak pump signal modulates the SQUID inductance, resulting in a single time-varying boundary condition, and we detect all four quadratures of the microwave radiation emitted at two different frequencies separated by 0.7 GHz. Power calibration is done in situ, and we find positive logarithmic negativity and two-mode squeezing below the vacuum in the observed radiation, indicating entanglement.
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