| 1. |
- Phillips, Helen R. P., et al.
(author)
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Global distribution of earthworm diversity
- 2019
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 366:6464, s. 480-
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Journal article (peer-reviewed)abstract
- Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, and biomass. We found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms. However, high species dissimilarity across tropical locations may cause diversity across the entirety of the tropics to be higher than elsewhere. Climate variables were found to be more important in shaping earthworm communities than soil properties or habitat cover. These findings suggest that climate change may have serious implications for earthworm communities and for the functions they provide.
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| 2. |
- Vidner, Olle, 1990-
(author)
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On Multi-Disciplinary Optimization in Engineer-to-Order Product Configuration
- 2023
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Licentiate thesis (other academic/artistic)abstract
- Customized products are becoming increasingly common, and increasingly important for maintaining a competitive advantage in certain industries. Being able to quickly and accurately respond to unique customer requirements can provide a competitive edge or even be the only path to survival. In practice, configurators are commonly used to manage the customization process, gathering the customer’s requirements and suggesting feasible solutions to the customer’s problem.Fostering and maintaining a viable product customization offering is not easy. A particularly challenging category of products is one where an extensive engineering effort might be needed to even produce a reliable estimate of the product’s price. These products are usually referred to as engineer-to-order (ETO) products.Prior work has pointed out the potential of using optimization as part of configuration solutions for ETO products, but the literature is limited in its extent and does not clearly prescribe how to structure and approach such solutions.This thesis outlines a conceptual and technical architecture for implementing optimization-based configuration solutions. Reusable primitives for supporting the routines involved in this architecture are provided. These findings are verified through application and evaluation within two industrial case studies, also yielding important industrial needs to cover in the future research and development of the proposed framework. By examining three additional case studies, common issues in the development and deployment of design automation (DA) systems are identified.Successful implementation of the proposed framework for optimization-based configurators can lead to two main benefits. First, engineering configurator prototypes can be developed rapidly, to test the viability of configurator projects – a category of projects prone to expensive failures. Second, optimization-based configurators can be used to support rapid design space exploration in early product development stages, leading to enhanced product knowledge in a critical phase, and in turn, increased product value.
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| 3. |
- Aeddula, Omsri, 1993-, et al.
(author)
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AI-driven Ossification Assessment in Knee MRI : A Product-Service System Development for Informed Clinical Decision-Making
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Other publication (other academic/artistic)abstract
- Background: Traditionally, assessing the degree of ossification in the epiphyseal plate for growth plate development relies on manual evaluation, which can be inefficient due to the complexities of the distal femoral epiphysis anatomy. Existing methods lack efficient detection techniques.Method: This study proposes an AI-based decision support system, designed within a product-service system (PSS) framework, to automate ossification assessment and detection of the distal femoral epiphysis in knee magnetic resonance imaging (MRI) data. The system leverages advanced machine learning techniques, specifically two Convolutional Neural Networks (CNNs), combined with computer vision techniques. This intelligent system analyzes MRI slices to predict the optimal slice for analysis and identify variations in the degree of ossification within individual datasets.Results: The proposed method's effectiveness is demonstrated using a set of T2-weighted gradient echo grayscale knee MRI data. The system successfully detects the complex anatomy of the distal femoral epiphysis, revealing variations in the degree of ossification ranging from completely closed/open to fully open/closed regions.Conclusions: This study presents a robust and efficient AI-based method, integrated within a PSS framework, for measuring the degree of ossification in the distal femoral epiphysis. This approach automates ossification assessment, providing valuable insights for clinical decision-making by clinicians and forensic practitioners. The PSS framework ensures seamless integration of the AI technology into existing workflows.
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| 4. |
- Aeddula, Omsri, 1993-
(author)
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Data-Driven Decision Support Systems for Product Development - A Data Exploration Study Using Machine Learning
- 2021
-
Licentiate thesis (other academic/artistic)abstract
- Modern product development is a complex chain of events and decisions. The ongoing digital transformation of society, increasing demands in innovative solutions puts pressure on organizations to maintain, or increase competitiveness. As a consequence, a major challenge in the product development is the search for information, analysis, and the build of knowledge. This is even more challenging when the design element comprises complex structural hierarchy and limited data generation capabilities. This challenge is even more pronounced in the conceptual stage of product development where information is scarce, vague, and potentially conflicting. The ability to conduct exploration of high-level useful information using a machine learning approach in the conceptual design stage would hence enhance be of importance to support the design decision-makers, where the decisions made at this stage impact the success of overall product development process.The thesis aims to investigate the conceptual stage of product development, proposing methods and tools in order to support the decision-making process by the building of data-driven decision support systems. The study highlights how the data can be utilized and visualized to extract useful information in design exploration studies at the conceptual stage of product development. The ability to build data-driven decision support systems in the early phases facilitates more informed decisions.The thesis presents initial descriptive study findings from the empirical studies, showing the capabilities of the machine learning approaches in extracting useful information, and building data-driven decision support systems. The thesis initially describes how the linear regression model and artificial neural networks extract useful information in design exploration, providing support for the decision-makers to understand the consequences of the design choices through cause-and-effect relationships on a detailed level. Furthermore, the presented approach also provides input to a novel visualization construct intended to enhance comprehensibility within cross-functional design teams. The thesis further studies how the data can be augmented and analyzed to extract the necessary information from an existing design element to support the decision-making process in an oral healthcare context.
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| 5. |
- Aeddula, Omsri, 1993-
(author)
-
Navigating Data Challenges: AI-Driven Decision Support for Product-Service System Development
- 2024
-
Doctoral thesis (other academic/artistic)abstract
- Solution providers are transitioning from product-centric models to service-oriented solutions. This shift has led to the rise of Product-Service Systems (PSS), which offer a holistic approach by integrating physical products with associated services. However, the inherent complexity and collaborative nature of PSS development present a significant challenge: information gathering, analysis, and knowledge building. This is further amplified in the early stages of PSS development due to data challenges such as uncertainty, ambiguity, and complexity. This complicates informed decision-making, potentially leading to the risk of sub-optimal outcomes and impacting the success of final offerings.This research proposes an AI-powered data analysis approach to address these data challenges and augment the decision-making process of PSS development. The focus is on supporting early-stage decision-making, as decisions made at this stage greatly impact the success of final solutions. The research investigates how data can be utilized and visualized to extract actionable insights, ultimately facilitating informed decision-making.The presented research demonstrates that AI-powered data analysis effectively supports informed decision-making in early-stage PSS development. By extracting actionable insights from complex data, handling data limitations, and enabling informed strategic decisions, knowledge sharing, and collaboration are facilitated among stakeholders. Furthermore, integrating AI with visualization tools fosters knowledge building and a deeper understanding of system behavior, ultimately leading to more successful PSS solutions. The efficacy of AI-powered data analysis for handling diverse data types across application domains is demonstrated, potentially leading to benefits such as a deeper understanding of system behavior and proactive solution strategies. These advancements contribute to developing decision support systems specifically for PSS development.Overall, this research demonstrates the efficacy of AI-powered data analysis in overcoming data challenges and empowering decision-makers in early-stage PSS development. This translates to more informed choices, leading to the creation of successful and efficient PSS solutions.
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| 6. |
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| 7. |
- Byström, Johan, et al.
(author)
-
A numerical study of the convergence in stochastic homogenization
- 2004
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In: Journal of Analysis and Applications. - 0972-5954. ; 2:3, s. 159-171
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Journal article (peer-reviewed)abstract
- This note makes the link between theoretical results on stochastic homogenization and effective computation of averaged coefficients for diffusion operators in random media. Examples of how to construct relevant random media and numerical results on the effective coefficients are given.
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| 8. |
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| 9. |
- Pilthammar, Johan, 1987-, et al.
(author)
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Framework for Simulation-Driven Design of Stamping Dies Considering Elastic Die and Press Deformations
- 2017
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In: PROCEEDINGS OF THE 20TH INTERNATIONAL ESAFORM CONFERENCE ON MATERIAL FORMING (ESAFORM 2017). - : American Institute of Physics (AIP). - 9780735415805
-
Conference paper (peer-reviewed)abstract
- Sheet metal forming (SMF) simulations are used extensively throughout the development phase of industrialstamping dies. In these SMF simulations, the die and press are normally considered as rigid. Previous research has howevershown that elastic deformation in these parts has a significant negative impact on process performance. This paperdemonstrates methods for counteracting these negative effects, with a high potential for improved production support anda reduced lead time through a shorter try-out process. A structural finite element model (FE-model) of a simplified die isstudied. To account for elastic deformation, the blankholder surfaces are first virtually reworked by adjusting the nodalpositions on the die surfaces attaining a pressure distribution in accordance to the design phase SMF simulations with rigidsurfaces. The elastic FE-model with reworked surfaces then represents a stamping die in running production. The die isnow assumed to be exposed to changed process conditions giving an undesired blankholder pressure distribution. Thechanged process conditions could for example be due to a change of press line. An optimization routine is applied tocompensate the negative effects of the new process conditions. The optimization routine uses the contact forces acting onthe shims of the spacer blocks and cushion pins as optimization variables. A flexible simulation environment usingMATLAB and ABAQUS is used. ABAQUS is executed from MATLAB and the results are automatically read back intoMATLAB. The suggested optimization procedure reaches a pressure distribution very similar to the initial distributionassumed to be the optimum, and thereby verifying the method. Further research is needed for a method to transform thecalculated forces in the optimization routine back to shims thicknesses. Furthermore, the optimization time is relativelylong and needs to be reduced in the future for the method to reach its full potential.
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| 10. |
- Tatipala, Sravan, 1993-, et al.
(author)
-
Introductory study of sheet metal forming simulations to evaluate process robustness
- 2018
-
In: IOP Conference Series: Materials Science and Engineering. - : Institute of Physics Publishing (IOPP).
-
Conference paper (peer-reviewed)abstract
- The ability to control quality of a part is gaining increased importance with desires to achieve zero-defect manufacturing. Two significant factors affecting process robustness in production of deep drawn automotive parts are variations in material properties of the blanks and the tribology conditions of the process. It is imperative to understand how these factors influence the forming process in order to control the quality of a formed part. This paper presents a preliminary investigation on the front door inner of a Volvo XC90 using a simulation-based approach. The simulations investigate how variation of material and lubrication properties affect the numerical predictions of part quality. To create a realistic lubrication profile in simulations, data of pre-lube lubrication amount, which is measured from the blanking line, is used. Friction models with localized friction conditions are created using TriboForm and is incorporated into the simulations. Finally, the Autoform-Sigmaplus software module is used to create and vary parameters related to material and lubrication properties within a user defined range. On comparing and analysing the numerical investigation results, it is observed that a correlation between the lubrication profile and the predicted part quality exists. However, variation in material properties seems to have a low influence on the predicted part quality. The paper concludes by discussing the relevance of such investigations for improved part quality and proposing suggestions for future work.
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| 11. |
- Wall, Maria, et al.
(author)
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Mild Climates
- 2007
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In: Sustainable Solar Housing. Strategies and Solutions. Volume 1.. - 9781844073252 ; Volume 1, s. 237-241
-
Book chapter (other academic/artistic)
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| 12. |
- Wall, Maria, et al.
(author)
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Temperate Climates
- 2007
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In: Sustainable Solar Housing. Strategies and Solutions. Volume 1.. - 9781844073252 ; Volume 1, s. 179-185
-
Book chapter (other academic/artistic)
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Aad, G., et al.
(author)
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Readiness of the ATLAS Tile Calorimeter for LHC collisions
- 2010
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:4, s. 1193-1236
-
Journal article (peer-reviewed)abstract
- The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of the timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems' precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%.
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| 18. |
- Aad, G., et al.
(author)
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Studies of the performance of the ATLAS detector using cosmic-ray muons
- 2011
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 71:3
-
Journal article (peer-reviewed)abstract
- Muons from cosmic-ray interactions in the atmosphere provide a high-statistics source of particles that can be used to study the performance and calibration of the ATLAS detector. Cosmic-ray muons can penetrate to the cavern and deposit energy in all detector subsystems. Such events have played an important role in the commissioning of the detector since the start of the installation phase in 2005 and were particularly important for understanding the detector performance in the time prior to the arrival of the first LHC beams. Global cosmic-ray runs were undertaken in both 2008 and 2009 and these data have been used through to the early phases of collision data-taking as a tool for calibration, alignment and detector monitoring. These large datasets have also been used for detector performance studies, including investigations that rely on the combined performance of different subsystems. This paper presents the results of performance studies related to combined tracking, lepton identification and the reconstruction of jets and missing transverse energy. Results are compared to expectations based on a cosmic-ray event generator and a full simulation of the detector response.
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| 19. |
- Aad, G., et al.
(author)
-
The ATLAS Inner Detector commissioning and calibration
- 2010
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 787-821
-
Journal article (peer-reviewed)abstract
- The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1 +/- 0.9 mu m and a relative momentum resolution sigma (p) /p=(4.83 +/- 0.16)x10(-4) GeV(-1)xp (T) have been measured for high momentum tracks.
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| 20. |
- Aad, G., et al.
(author)
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The ATLAS Simulation Infrastructure
- 2010
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 823-874
-
Journal article (peer-reviewed)abstract
- The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for large-scale production of events on the LHC Computing Grid. This simulation requires many components, from the generators that simulate particle collisions, through packages simulating the response of the various detectors and triggers. All of these components come together under the ATLAS simulation infrastructure. In this paper, that infrastructure is discussed, including that supporting the detector description, interfacing the event generation, and combining the GEANT4 simulation of the response of the individual detectors. Also described are the tools allowing the software validation, performance testing, and the validation of the simulated output against known physics processes.
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| 21. |
- Aeddula, Omsri, 1993-, et al.
(author)
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AI-Driven Comprehension of Autonomous Construction Equipment Behavior for Improved PSS Development
- 2024
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In: Proceedings of the 57th Annual Hawaii International Conference on System Sciences. - : University of Hawai'i at Manoa. - 9780998133171 ; , s. 1017-1026
-
Conference paper (peer-reviewed)abstract
- This paper presents an approach that utilizes artificial intelligence techniques to identify autonomous machine behavior patterns. The context for investigation involves a fleet of prototype autonomous haulers as part of a Product Service System solution under development in the construction and mining industry. The approach involves using deep learning-based object detection and computer vision to understand how prototype machines operate in different situations. The trained model accurately predicts and tracks the loaded and unloaded machines and helps to identify the data patterns such as course deviations, machine failures, unexpected slowdowns, battery life, machine activity, number of cycles per charge, and speed. PSS solutions hinge on efficiently allocating resources to meet the required site-level output. Solution providers can make more informed decisions at the earlier stages of development by using the AI techniques outlined in the paper, considering asset management and reallocation of resources to account for unplanned stoppages or unexpected slowdowns. Understanding machine behavioral aspects in early-stage PSS development could enable more efficient and customized PSS solutions.
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| 22. |
- Aeddula, Omsri, 1993-, et al.
(author)
-
AI-Driven Predictive Maintenance for Autonomous Vehicles for Product-Service System Development
- 2024
-
Conference paper (peer-reviewed)abstract
- The paper presents an Artificial Intelligence-driven approach to predictive maintenance for Product-Service System (PSS) development. This study focuses on time-based and condition-based maintenance, leveraging variational autoencoders to identify both predicted and unpredicted maintenance issues in autonomous haulers. By analyzing data patterns and forecasting future values, this approach enables proactive maintenance and informed decision-making in the early stages of PSS development. The inclusion of interaction terms enhances the model’s ability to capture the interdependencies among system components, addressing hidden failure modes. Comprehensive evaluations demonstrate the effectiveness and robustness of the developed models, showcasing resilience to noise and variations in operational data. The integration of predictive maintenance with PSS development offers a strategic advantage, providing insights into vehicle performance early in the development phases. This empowers decision-makers for efficient resource allocation and proactive maintenance planning. The research highlights the limitations and potential areas of improvement while also emphasizing the practical applicability and significance of the developed models in enhancing PSS development.
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| 23. |
- Aeddula, Omsri, 1993-, et al.
(author)
-
Artificial Neural Networks Supporting Cause-and-Effect Studies in Product–Service System Development
- 2021
-
In: Design for Tomorrow—Volume 2. - Singapore : Springer. - 9789811601187 ; , s. 53-64
-
Conference paper (peer-reviewed)abstract
- A data analysis method based on artificial neural networks aiming to support cause-and-effect analysis in design exploration studies is presented. The method clusters and aggregates the effects of multiple design variables based on the structural hierarchy of the evaluated system. The proposed method is exemplified in a case study showing that the predictive capability of the created, clustered, a dataset is comparable to the original, unmodified, one. The proposed method is evaluated using coefficient-of-determination, root mean square error, average relative error, and mean square error. Data analysis approach with artificial neural networks is believed to significantly improve the comprehensibility of the evaluated cause-and-effect relationships studying PSS concepts in a cross-functional team and thereby assisting the difficult and resource-demanding negotiations process at the conceptual stage of the design.
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| 24. |
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| 25. |
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| 26. |
- Amnå, Erik, et al.
(author)
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En halv miljard av statens pengar riskerar att slösas bort
- 2007
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In: Göteborgs-Posten. ; 2007-09-13, s. 47-47
-
Journal article (pop. science, debate, etc.)abstract
- Minskade anslag gör att den årliga undersökningen om våra levnadsförhållanden hotas att halveras. Det kan drabba redan svaga grupper som äldre, invandrare och ensamstående föräldrar.
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| 27. |
- Andersson, Fredrik W., 1974, et al.
(author)
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Sick listing-Partly a family phenomenon?
- 2011
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In: Journal of Socio-Economics. - : Elsevier BV. - 1053-5357. ; 40:5, s. 496-502
-
Journal article (peer-reviewed)abstract
- Being sick listed is not always identical to being ill; it is rather a behaviour associated with illness. In this paper we have analysed whether there is a higher risk of becoming sick listed if a family member has been sick listed earlier-partly a family phenomenon. This aspect of sick listing has never been investigated before. Our results indicate that an individual's risk of being sick listed in 2007 was higher if he/she had family members who had been sick listed in 2006. This may be a sign for an existing " sick listing culture" -social norms within families. © 2010 Elsevier Inc.
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| 28. |
- Andersson, Johan, et al.
(author)
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A Framework for Analysis of Timing and Resource Utilization targeting Complex Embedded Systems
- 2006
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In: ARTES - A network for Real-Time research and graduate Education in Sweden 1997 - 2006. - Uppsala : Department of Information Technology. - 9150618598 ; , s. 297-329
-
Book chapter (other academic/artistic)abstract
- A problem in common of many complex software systems embedded in industrialproducts is the absence of analyzability as formal models of the systembehavior does not exist. When performing maintenance of such systems it ishard to predict how changes will impact specific system properties related totiming and resource utilization and there is therefore a significant risk of runninginto problems with unexpected side-effects of the changes made, whichincreases development time required and costs.In this paper we present the ART Framework, a set of methods and toolsthat enable behavior impact analysis for existing industrial real-time systems.The ART Framework enables developers of complex software systems to identifyproblematic side-effects of a proposed design before vast resources havebeen invested in implementation and testing. This reduces the risk of expensiveand time-consuming problems discovered late in a development projectand also reduces the risk releasing software containing latent critical errors.
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| 29. |
- Andersson, Johan, et al.
(author)
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Extracting Simulation Models from Complex Embedded Real-Time Systems
- 2006
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In: Proceedings of the 2006 International Conference on Software Engineering Advances, ICSEA'06, Tahiti, French Polynesia. - 0769527035 ; , s. Article number 4031792-
-
Conference paper (peer-reviewed)abstract
- A modeling process is presented for extracting timingaccurate simulation models from complex embedded real-time systems. The process is supported by two complementary methods for tool-supported model extraction, Model Synthesis and Hybrid Model Extraction. The generated models enable impact analysis for complex real-time systems with respect to dynamic system properties, such as timing and resource usage. This can make software maintenance more predictable with respect to time-to-market and development costs, since timing errors can be identified early and avoided. The contribution of the paper is the modeling process, the Hybrid Model Extraction method and an interactive modeling tool, MASS, designed to support Hybrid Model Extraction of large implementations in C.
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| 30. |
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| 31. |
- Berg, Lotta, et al.
(author)
-
Yttrande från SLUs vetenskapliga råd för djurskydd om hållande av hund och katt
- 2018
-
Other publication (other academic/artistic)abstract
- Detta yttrande är skrivet på uppdrag av Jordbruksverket i samband med verkets översyn av föreskrifterna för hund och katt. För att Jordbruksverkets föreskrifter ska vara väl förankrade i den senaste forskningen önskar verket inhämta underlag från det vetenskapliga rådet för djurskydd vid Sveriges lantbruksuniversitet, specifikt gällande områdena rörelsebehov, social kontakt och avvänjning.
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| 32. |
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| 33. |
- Bertoni, Alessandro, 1985-, et al.
(author)
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MODEL-DRIVEN PRODUCT SERVICE SYSTEMS DESIGN : THE MODEL-DRIVEN DEVELOPMENT AND DECISION SUPPORT (MD3S) APPROACH
- 2021
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In: Proceedings of the Design Society 2021. - : Cambridge University Press. ; , s. 2137-2146
-
Conference paper (peer-reviewed)abstract
- The paper presents a Model-Driven approach for Product-Service System (PSS) Design promoting an increased digitalization of the PSS design process based on the combination of data-driven design (DDD) activities and value-driven design (VDD) methods. The approach is the results of an 8-year long research profile named (omitted for blind review) featuring the collaboration between (omitted for blind review) and nine industrial companies, in the field of PSS Design. It combines VDD models and the supporting data-driven activities in the frame of PSS design and aligns with the product value stream and the knowledge value stream in the product innovation process as described by Kennedy et al. (2008). The paper provides a high-level overview of the approach describing the different stages and activities, and provides references to external scientific contributions for more exhaustive descriptions of the research rationale and validity. The approach is meant to ultimately drive the development and implementation of a simulation environment for cross-functional and multi-disciplinary decision making in PSS, named Model-Driven Decision Arena, describe in the concluding part of the paper.
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| 34. |
- Bertoni, Marco, 1980-, et al.
(author)
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Life cycle simulation to support cross-disciplinary decision making in early PSS design
- 2019
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In: Procedia CIRP. - : Elsevier. ; , s. 260-265
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Conference paper (peer-reviewed)abstract
- The development of early-stage simulation capabilities is a critical step in the quest for ‘frontloading’ early stage PSS design activities, reducing the cost and risk for rework associated with sub-optimal decisions. This paper describes how life cycle simulations, based on a Discrete Event approach, can be applied to support cross-disciplinary decision making in PSS design, facilitating the identification of the most valuable hardware configuration for a given business model. The proposed approach is exemplified in a case study related to the design of a zero-emission asphalt compactor, which is part of a product-oriented and use-oriented PSS offer. Co-located physical meetings and interviews with industrial practitioners highlight the role played by the simulation as an enabler for leveraging tacit knowledge sharing across roles and disciplines in the organization, making possible to explore the design space with more rigor. They further reveal the need to exploit data mining techniques and to develop new constructs able to inform decision makers of maturity and impact of models used in a specific decision scenario.
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| 35. |
- Bertoni, Marco, 1980-, et al.
(author)
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Model Driven Decision Arena : an aerospace study
- 2018
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In: Proceedings of the International Design Conference. - : The Design Society. - 9789537738594 ; , s. 171-182
-
Conference paper (peer-reviewed)abstract
- The concept of Decision Theatre (DT) is of great interest to leverage knowledge sharing in early stage design decision events. Yet, few contributions show how to configure a DT to support design space exploration and concept selection in cross-functional teams. This paper describes the development of a model-driven decision arena (MDDA) for aero-engine sub-system design. After presenting the descriptive study findings, it illustrates the overall logic of the MDDA environment and exemplifies its use in a case study related to the design of a turbine real structure (TRS) for commercial use.
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| 36. |
- Broman, Göran, et al.
(author)
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Introductory Optimisation Study of a Rammer Soil Compactor Machine
- 2001
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Conference paper (peer-reviewed)abstract
- Rammer compactor machines perform dynamic soil compaction. The complexity of this machine type makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for prediction of the dynamic behaviour of the machine and a procedure for optimisation as design parameters are changed during product development. In this paper a theoretical model of the rammer machine in combination with a soil model is described. This multi-body dynamics system is solved numerically. The system is non-linear and chaotic behaviour is possible. This parameter sensitivity emphasises the need for this kind of simulations in the product development process. A fairly regular behaviour is necessary for a predictable and safe operation. Parameter combinations giving too irregular behaviour are non-feasible. The energy transfer rate from the rammer machine into the soil is used as the objective function for optimisation. Multi-start Sequential Quadratic Programming for optimum search is used. To cover the design space well a Uniform Experimental Design is used for selection of starting points. This procedure proves to work well for the problem of this introductory study. The study shows a significant potential for improved compaction capacity although considering only the three design parameters that are most easily changed in practice. Approximately the same optimum is obtained both for operation on soft soil and hard soil, so a good all-round design seems possible. Including this theoretical support in the product development process should make it much more effective in finding optimum designs, also for other machines of similar type.
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| 37. |
- Byggeth, Sophie, et al.
(author)
-
Introductory Procedure for Sustainability-Driven Design Optimization
- 2007
-
Conference paper (peer-reviewed)abstract
- In response to the increasingly competitive global market, there is a growing interest in design optimization. Being able to include aspects of socio-ecological sustainability in product design should aid companies to both improve current competitiveness and to identify viable long-term investment paths and new business opportunities in the evolving sustainability-driven market. A case study of a water jet cutting machine is used to illustrate a new iterative optimization procedure that combines a technical assessment with a sustainability assessment. Sustainability assessment methods/tools are first used to identify prominent sustainability problems from present-day flows and practices (“societal indicators”) and to generate ideas of long-term solutions and visions. Based on this, preliminary ideas about likely desirable changes in machine properties are obtained. Technical investigations are then performed to assess if/how these particularly desirable changes in machine properties could in principle be realized through changes in design variables. After that, obtainable changes are fed back to a new and more refined sustainability assessment to find out the societal implications of these changes. This may in turn result in other desirable design changes, which may call for a new and more refined technical assessment, etcetera. The experience from the case study indicates that the suggested integrated and iterative working procedure should be able to add information about socio-ecological impacts of product properties and influence design criteria used in prioritisation situations during product development.
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| 38. |
- Byström, Johan, et al.
(author)
-
Bounds and numerical results for the homogenized degenerated p-Poisson equation
- 2004
-
In: Applications of Mathematics. - 0862-7940 .- 1572-9109. ; 49:2, s. 111-122
-
Journal article (peer-reviewed)abstract
- In this paper we derive upper and lower bounds on the homogenized energy density functional corresponding to degenerated p-Poisson equations. Moreover, we give some non-trivial examples where the bounds are tight and thus can be used as good approximations of the homogenized properties. We even present some cases where the bounds coincide and also compare them with some numerical results.
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| 39. |
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| 40. |
- Byström, Johan, et al.
(author)
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Periodic approximation of elastic properties in random media
- 2006
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In: Advances in Algebra and Analysis. - 0973-2306. ; 1:2, s. 103-113
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Journal article (peer-reviewed)abstract
- Most papers on stochastic homogenization either deal with theoretical aspects or with questions regarding computational issues. Since the theoretical analysis involves the solution of a problem which is stated in a abstract probability space, it is not clear how the two areas are connected. In previous works this problem has not been considered. However, recently Bourgeat and Piatnitski investigated this connection in the scalar case for second order operators of divergence form. They proved that in the limit, the method of periodic approximation gives the same effective properties as in stochastic homogenization. In this paper we prove similar results for the vector valued case, which appears in e.g. the theory of elasticity. Moreover, we provide a numerical analysis of the results.
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| 41. |
- Byström, Johan, et al.
(author)
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Reiterated homogenization of degenerate nonlinear elliptic equations
- 2002
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In: Chinese Annals of Mathematics. Series B. - 0252-9599 .- 1860-6261. ; 23:3, s. 325-334
-
Journal article (peer-reviewed)abstract
- The authors study homogenization of some nonlinear partial differential equations of the form _ div (a (hx, h2 x, Duh)) = f , where a is periodic in the rst two arguments and monotone in the third. In particular the case where a satis es degenerated structure conditions is studied. It is proved that uh converges weakly in W0 1,1 (Ω) to the unique solution of a limit problem as h → ∞ . Moreover, explicit expressions for the limit problem are obtained.
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| 42. |
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| 43. |
- Chowdhery, Syed Azad, 1985-
(author)
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A data-driven approach for Product-Service Systems design : Using data and simulation to understand the value of a new design concept
- 2020
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Licentiate thesis (other academic/artistic)abstract
- Global challenges such as increasingly competitive markets, low-cost competition, shorter lead time demands, and high quality/value output are transforming the business model of the company to focus beyond the performance requirements. In order to meet these challenges, companies are highly concerned with the customer perceived value, which is to connect the product with the customer in a better way and become more proactive to fulfil the customer needs, via function-oriented business models and Product-Service Systems.In literature, the conceptual phase is distinguished as the most critical phase of the product development process. Many authors have recognized the improvement of design in the conceptual phase as the mean to deliver a successful product in the market. At the decision gate, where concepts are selected for further development, the design team needs knowledge/data about the long-term consequences of their early decision, to see how changes in design propagate to the entire lifecycle of the product.The main goal of the thesis is to describe how the design of Product-Service Systems in the conceptual phase can be improved through the use of a data-driven approach. The latter provides an opportunity to enhance decision making and to provide better support at the early development phase. The study highlights how data are managed and used in current industrial setting and indicates the room for improvement with current practices. The thesis further provides guidelines to efficiently use data into the modelling and simulation activities to increase design knowledge. As a result of this study, a data-driven approach emerged to support the early design decision. The thesis presents initial descriptive study findings from the empirical investigations, showing a model-based approach that creates awareness about the value of a new design concept, thus acting as a key enabler to use data in design. This will create a link between the product engineering characteristic to the high-level attributes of customer satisfaction and provider’s long-term profitability. The preliminary results indicate that the application of simulation models to frontload the early design stage creates awareness about how performance can lead to value creation, helping multidisciplinary teams to perform quick trade-off and what-if analysis on design configurations. The proposed framework shows how data from various sources are used through a chain of simulations to understand the entire product lifecycle. The proposed approach holds a potential to improve the key performance indicators for Product-Service Systems development: lead time, design quality, cost and most importantly deliver a value-added product to the customer.
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| 44. |
- Chowdhery, Syed Azad, 1985-, et al.
(author)
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A data-driven design framework for early stage PSS design exploration
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Other publication (other academic/artistic)abstract
- Ubiquitous and pervasive computing holds great potential in the domain of Product-Service Systems to introduce a model-driven paradigm for decision support. Data-driven design is often discussed as a critical enabler for developing simulation models that comprehensively explore the PSS design space for complex systems, linking of performances to customer and provider value. Emerging from the findings of two empirical studies conducted in collaboration with multinational manufacturing companies in the business-to-business market, this paper defines a data-driven framework to support engineering teams in exploring, early in the design process, the available design space for Product-Service Systems from a value perspective. Verification activities show that the framework and modeling approach is considered to fill a gap when it comes to stimulating value discussions across functions and organizational roles, as well as to grow a clearer picture of how different disciplines contribute to the creation of value for new solutions.
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| 45. |
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| 46. |
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| 47. |
- Englund, Thomas, et al.
(author)
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Automated updating of simplified component models for exhaust system dynamics simulations
- 2002
-
Conference paper (peer-reviewed)abstract
- To facilitate overall lay-out optimisation simplified component models for dynamics simulations of automobile exhaust systems are desired. Such optimisation could otherwise be computationally expensive, especially when non-linear analyses are necessary. Suggestions of simplified models of the mufflers and the catalyst are given. To account for the flexibility at the connections between those components and the pipes short beam elements with individual properties are introduced at these locations. An automated updating procedure is developed to determine the properties of these beam elements. Results from an experimental modal analysis are used as the reference. The theoretical model of the exhaust system is built in the finite element software ABAQUS. The updating procedure uses the sequential quadratic programming algorithm included in the Optimization Toolbox of the software MATLAB to minimise the sum of the differences between experimentally and theoretically obtained natural frequencies. Constraints are used on the correlation between the experimentally and theoretically obtained mode shapes by considering the MAC-matrix. Communication between the two software packages is established by an in-house MATLAB script. The correlation between results from the updated theoretical model and the experimental results is very good, which indicates that the updating procedure works well.
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| 48. |
- Englund, Thomas, et al.
(author)
-
Dynamic characteristics of a combined bellows and liner flexible joint
- 2004
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In: Journal of Automobile Engineering. - : Professional Engineering Publishing. - 0954-4070. ; 218:5, s. 485-493
-
Journal article (peer-reviewed)abstract
- A bellows combined with an inside liner and an outside braid is commonly used as a flexible joint in automobile exhaust systems to reduce transmission of engine movements to the exhaust system. It greatly influences the dynamics of the complete system. Understanding of its dynamic characteristics and a modelling method that facilitates systems simulation are therefore desired. This has been obtained in earlier works for the bellows itself. In this work an approach to the modelling of the combined bellows and liner joint is suggested and experimentally verified. Simulations and measurements show that the liner adds significant non-linearity and makes the characteristics of the joint complex. Results are presented for the axial and the bending load cases. In torsion, influence of the liner is negligible. Peak responses are significantly reduced when the excitation level approximately corresponds to the friction limit of the liner. The complexity of the combined bellows and liner joint is important to know of and consider in exhaust system design and proves the necessity of including a model of the liner in the theoretical joint model when this type of liner is present in the real joint to be simulated.
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| 49. |
- Englund, Thomas, et al.
(author)
-
Significance of non-linearity and component-internal vibrations in an exhaust system
- 2002
-
Conference paper (peer-reviewed)abstract
- To facilitate overall lay-out optimisation inexpensive dynamics simulation of automobile exhaust systems is desired. Identification of possible non-linearity as well as finding simplified component models is then important. A flexible joint is used between the manifold and the catalyst to allow for the motion of the engine and to reduce the transmission of vibrations to the rest of the exhaust system. This joint is significantly non-linear due to internal friction, which makes some kind of non-linear analysis necessary for the complete exhaust system. To investigate the significance of non-linearity and internal vibrations of other components a theoretical and experimental modal analysis of the part of a typical exhaust system that is downstream the flexible joint is performed. It is shown that non-linearity in this part is negligible. It is also shown that shell vibrations of the catalyst and mufflers as well as ovalling of the pipes are negligible in the frequency interval of interest. The results implies, for further dynamics studies, that the complete system could be idealised into a linear sub-system that is excited via the non-linear flexible joint, that the pipes could be modelled with beam elements and that the other components within the linear sub-system could also be modelled in a simplified way. Such simplified component models are suggested. The agreement between theoretical and experimental results is very good, which indicates the validity of the simplified modelling.
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| 50. |
- Gadd, Gustaf, et al.
(author)
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A Nonlinear Relation between Body Mass Index and Long-Term Poststroke Functional Outcome-The Importance of Insulin Resistance, Inflammation, and Insulin-like Growth Factor-Binding Protein-1.
- 2024
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In: International journal of molecular sciences. - 1661-6596 .- 1422-0067. ; 25:9
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Journal article (peer-reviewed)abstract
- Both high serum insulin-like growth factor-binding protein-1 (s-IGFBP-1) and insulin resistance (IR) are associated with poor functional outcome poststroke, whereas overweight body mass index (BMI; 25-30) is related to fewer deaths and favorable functional outcome in a phenomenon labeled "the obesity paradox". Furthermore, IGFBP-1 is inversely related to BMI, in contrast to the linear relation between IR and BMI. Here, we investigated s-IGFBP-1 and IR concerning BMI and 7-year poststroke functional outcome. We included 451 stroke patients from the Sahlgrenska Study on Ischemic Stroke (SAHLSIS) with baseline measurements of s-IGFBP1, homeostasis model assessment of IR (HOMA-IR), BMI (categories: normal-weight (8.5-25), overweight (25-30), and obesity (>30)), and high-sensitivity C-reactive protein (hs-CRP) as a measure of general inflammation. Associations with poor functional outcome (modified Rankin scale [mRS] score: 3-6) after 7 years were evaluated using multivariable binary logistic regression, with overweight as reference due to the nonlinear relationship. Both normal-weight (odds-ratio [OR] 2.32, 95% confidence interval [CI] 1.30-4.14) and obese (OR 2.25, 95% CI 1.08-4.71) patients had an increased risk of poor functional outcome, driven by deaths only in the normal-weight. In normal-weight, s-IGFBP-1 modestly attenuated (8.3%) this association. In the obese, the association was instead attenuated by HOMA-IR (22.4%) and hs-CRP (10.4%). Thus, a nonlinear relation between BMI and poor 7-year functional outcome was differently attenuated in the normal-weight and the obese.
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