| 1. |
- Liu, Yu
(author)
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Integrating life cycle assessment into simulation-based decision support
- 2022
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Licentiate thesis (other academic/artistic)abstract
- Increasing marketing and legislative requirements put heavy demands on the environmental performance of future transportation solutions. The resulting need to reduce total environmental impacts presents both challenges and opportunities to the transport sector as a whole, including the automotive industry. Life cycle assessment (LCA) is commonly used to evaluate environmental performance in the automotive industry. However, the static nature of LCAlimits its usefulness for capturing dynamic environmental consequences in the manufacturing and operational phase. This thesis proposes a simulation-based approach to LCA that addresses this problem. Selected real-world case studies demonstrate the potential of the approach in both vehicle production processes and end-user applications. The work was preceded by a comprehensive review of the potential benefits and challenges of using simulation-based LCA in production processes. This review laid the foundation for the development and implementation of this method inthe automotive industry. Two real-world case studies demonstrate its value. The first was a waste collection case study in which LCA was integrated in an existing simulation-based decision support tool to optimize the company’s activities froma life cycle environmental impact perspective. A simultaneously developed simulation-based LCA model of an iron foundry production line extended the applicability of the method with a proposed decision support interpretation approach. The study shows that data and information from both simulation model and LCA databases can be integrated and utilized in the developed simulation-based LCA method. This allows different systems with different configurations to be combined to assess the relevant parameters, and eventually to provide information about overall environmental impacts to decision makers to improvethe environmental sustainability of the automotive industry.
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| 2. |
- Calmunger, Mattias
(author)
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High-Temperature Behaviour of Austenitic Alloys : Influence of Temperature and Strain Rate on Mechanical Properties and Microstructural Development
- 2013
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Licentiate thesis (other academic/artistic)abstract
- The global increase in energy consumption and the global warming from greenhouse gas emission creates the need for more environmental friendly energy production processes. Biomass power plants with higher efficiency could generate more energy but also reduce the emission of greenhouse gases, e.g. CO2. Biomass is the largest global contributor to renewable energy and offers no net contribution of CO2 to the atmosphere. One way to increase the efficiency of the power plants is to increase temperature and pressure in the boiler parts of the power plant.The materials used for the future biomass power plants, with higher temperature and pressure, require improved properties, such as higher yield strength, creep strength and high-temperature corrosion resistance. Austenitic stainless steels and nickel-base alloys have shown good mechanical and chemical properties at the operation temperatures of today’s biomass power plants. However, the performance of austenitic stainless steels at the future elevated temperatures is not fully understood.The aim of this licentiate thesis is to increase our knowledge about the mechanical performance of austenitic stainless steels at the demanding conditions of the new generation power plants. This is done by using slow strain rate tensile deformation at elevated temperature and long term hightemperature ageing together with impact toughness testing. Microscopy is used to investigate deformation, damage and fracture behaviours during slow deformation and the long term influence of temperature on toughness in the microstructure of these austenitic alloys. Results show that the main deformation mechanisms are planar dislocation deformations, such as planar slip and slip bands. Intergranular fracture may occur due to precipitation in grain boundaries both in tensile deformed and impact toughness tested alloys. The shape and amount of σ-phase precipitates have been found to strongly influence the fracture behaviour of some of the austenitic stainless steels. In addition, ductility is affected differently by temperature depending on alloy tested and dynamic strain ageing may not always lead to a lower ductility.
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| 3. |
- Galozy, Alexander, 1991-
(author)
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Data-driven personalized healthcare : Towards personalized interventions via reinforcement learning for Mobile Health
- 2021
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Licentiate thesis (other academic/artistic)abstract
- Medical and technological advancement in the last century has led to the unprecedented increase of the populace's quality of life and lifespan. As a result, an ever-increasing number of people live with chronic health conditions that require long-term treatment, resulting in increased healthcare costs and managerial burden to the healthcare provider. This increase in complexity can lead to ineffective decision-making and reduce care quality for the individual while increasing costs. One promising direction to tackle these issues is the active involvement of the patient in managing their care. Particularly for chronic diseases, where ongoing support is often required, patients must understand their illness and be empowered to manage their care. With the advent of smart devices such as smartphones, it is easier than ever to provide personalised digital interventions to patients, help them manage their treatment in their daily lives, and raise awareness about their illness. If such new approaches are to succeed, scalability is necessary, and solutions are needed that can act autonomously without costly human intervention. Furthermore, solutions should exhibit adaptability to the changing circumstances of an individual patient's health, needs and goals. Through the ongoing digitisation of healthcare, we are presented with the unique opportunity to develop cost-effective and scalable solutions through Artificial Intelligence (AI).This thesis presents work that we conducted as part of the project improving Medication Adherence through Person-Centered Care and Adaptive Interventions (iMedA) that aims to provide personalised adaptive interventions to hypertensive patients, supporting them in managing their medication regiment. The focus lies on inadequate medication adherence (MA), a pervasive issue where patients do not take their medication as instructed by their physician. The selection of individuals for intervention through secondary database analysis on Electronic Health Records (EHRs) was a key challenge and is addressed through in-depth analysis of common adherence measures, development of prediction models for MA and discussions on limitations of such approaches for analysing MA. Furthermore, providing personalised adaptive interventions is framed in the contextual bandit setting and addresses the challenge of delivering relevant interventions in environments where contextual information is significantly corrupted. The contributions of the thesis can be summarised as follows: (1) Highlighting the issues encountered in measuring MA through secondary database analysis and providing recommendations to address these issues, (2) Investigating machine learning models developed using EHRs for MA prediction and extraction of common refilling patterns through EHRs and (3) formal problem definition for a novel contextual bandit setting with context uncertainty commonly encountered in Mobile Health and development of an algorithm designed for such environments.
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| 4. |
- Johansson, Elisabeth, 1983-
(author)
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Managing Quality in a Service Context
- 2013
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Licentiate thesis (other academic/artistic)abstract
- In recent years, service organizations have had to increase the number of offerings they provide. These organizations face difficulties in changing their internal processes to provide high-quality offerings. With the increase in demand for delivered services and competitive organizations from low-cost countries, service organizations currently face several issues. Today’s service organizations combine products and services into a solution to improve their competitiveness. These organizations experience changes in customer expectations depending on what they offer. That is, expectations, demands, and wishes change depending on the offering that a customer uses. Thus, service organizations need to know how expectations for quality change based on offerings and how they can work to change certain emphasized quality aspects. Hence, the aim of this licentiate thesis is to contribute to the knowledge of how to manage quality in a service context.This licentiate thesis is based on three different studies. One study is based on a number of self-assessment studies conducted at 138 Swedish service organizations using a total of more than 5,000 respondents. In the second study, data was collected over a five-year period through a literature review, interviews, a document study, and observations to capture the quality profile and associated interventions. The second study was conducted in a service organization in the public transportation industry. In the third study, a literature review was performed to provide theoretical propositions for developing a conceptual model. The conceptual model was built on theories from product quality, service quality, service logic, and solutions.The findings revealed that a service organization could change the performance level of a quality principle if the correct interventions are used. Furthermore, a service organization immature in quality management emphasizes one or two quality principles and, after the initial phase focuses on other principles as well. Therefore, if a service organization wants to change its quality profile pattern, it must change its emphasis on certain norms and principles. A further finding is the proposed solution’s quality concept and its six quality dimensions: (i) reliability, (ii) flexibility, (iii) consistency, (iv) empathy, (v) approachability, and (vi) tangibility. Furthermore, a model connecting the empirical findings in a quality concepts model is proposed. This model shows that the need exists to change work activities if the service organization changes strategic direction, that is, changes the number of offerings offered.
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| 5. |
- Johansson, Mattias Erik, 1980
(author)
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Development and Use of Optical Remote Sensing Methods for Studies of Megacity Air Pollution and Volcanic Gas Emissions
- 2007
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Licentiate thesis (other academic/artistic)abstract
- Optical Remote Sensing Techniques offers the opportunity to, in real-time, obtain line averaged measurements of gases in the lower and upper atmosphere. These techniques easily offer themselves to automatization, which increases their usability for e.g. risk-assessment of remotely situated volcanoes and routine monitoring of air pollution levels in urban areas.In 2007, a milestone in human history will be passed when half of the world’s population will be living in urban areas. Of these approximately 300 millions will be living in Megacities, defined as urban agglomerations with more than 10 million people. These large urban settlements cause problems with air pollution, problems worsened by the use of low-efficiency combustion techniques. At the same time, approximately 500 million people are living near active volcanoes. People strongly affected by the risk these volcanoes pose on their surroundings and by the emissions of sulphuric and halogenic gases.This thesis deals with the development and use of one Optical Remote Sensing technique, Differential Optical Absorption Spectroscopy (DOAS), for studying air pollution in Megacities, applied to México City and Beijing, and for monitoring of emissions of volcanic gases. A measurement technique for determining the speed and altitude of a gas plume using a DOAS-based instrument has been developed. Also, a method for creating tomographic reconstructions of the gas concentration in a cross section of a gas plume has been developed together with a novel instrument for performing fixed point automatic measurements on gas plumes.
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| 8. |
- Johansson, Mattias, 1975
(author)
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Value creation and the challenge of joining forces: Evidence from open innovation and mergers and acquisitions
- 2022
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Licentiate thesis (other academic/artistic)abstract
- Value creation is pivotal for organizational survival, growth, and competitiveness. The topic has attracted a growing interest from scholars looking for new ways to analyze how firms create value for themselves and their stakeholders. The means of value creation involve a wide array of strategies, tools, and forms of interaction. Focusing on the challenges of joining forces, this thesis explores two commonly used practices in collaboration with others to create value: mergers and acquisitions (M&A) and open innovation (OI). Both practices are highly complex. Despite the common use, they often fail to deliver the intended outcome, for example, in terms of synergies, complementarities, and increased efficiency. This thesis consists of two empirical papers and an introductory chapter. The themes discussed in each of the enclosed papers investigates value creation and the challenges of joining forces with other organizations. Paper 1 introduces a novel business model lens to study post-merger integration in M&As. This study combines firm-level case study research (in the European material handling industry) on business models and M&A to explore how differences in business models affect value creation and synergy realization during postmerger integration. The case evidence suggests that business model congruence – the fit between merging business models, achieved through the careful stitching of business model components into a value-creating system – is a critical factor impacting post-merger integration. Paper 2 focuses on OI and explores the challenges to successful value creation in partnerships between large and small firms. Based on field studies and interview data, I uncover distinct challenges that large and small firms experience and what tactics can be used to address such challenges. This thesis contributes to the understanding of what impacts value creation when organizations join forces through M&A and OI. Emphasizing two common collaborative strategies with a novel theoretical approach allowed me to investigate the mechanisms for value creation at a more granular level than previously examined. The combined theme of the thesis adds to M&A, OI and strategic management literature by providing relevant insights on the impact of interorganizational relations and organizational differences on collaborative strategies. By integrating business models into the M&A literature, I expand the concept of strategic fit, offering an opportunity to rethink how synergies are created. My approach of focusing on OI partnerships between large and small firms contributes to the understanding of how value is created in a collaborative context by identifying how large and small firms engage in collaboration with very different perspectives and capabilities. Factors that, if not mitigated, hamper the relationship and intended value creation, respectively. Having identified these relational challenges, I present remedies that seek to establish mutual trust from the start of the partnership. By contributing to a new understanding of common strategies for creating value in collaboration with others, I derive implications for strategic similarity, synergy realization, and OI.
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| 9. |
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| 10. |
- Lundberg, Mattias
(author)
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Residual Stresses and Fatigue of Shot Peened Cast Iron
- 2013
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Licentiate thesis (other academic/artistic)abstract
- The complex geometry of cylinder head in heavy-duty diesel engine makes grey cast iron or compact graphite iron a perfect material choice due to its castability, thermal conductivity and damping capacity. To increase the efficiency of the engine, the fatigue property of the material needs to be improved. Shot peening is often used to increase the fatigue strength of components. The benefits are associated with the compressive stresses induced and with surface hardening. In this research project, these effects on grey and compact iron have been analyzed for different shot peening parameters using XRD, SEM and fatigue testing methods. The ultimate aim of the project is to increase the fatigue strength of cast irons by optimization of residual stresses.The XRD measurements and SEM examinations revealed that the shot peening parameters including shot size and peening intensity had significant influences on the resulted residual stresses and strain hardening while changing the coverage made little difference. Also differences in the peening results between the two materials were observed, which were ascribed to an effect of the different graphite morphology. Nevertheless, a residual stress profile similar to the one general considered to improve the fatigue strength in steels could be obtained in both grey and compact iron after shot peening.The axial fatigue testing with R=-1 on the grey iron showed that peening using large shot size and high peening intensity (heavy shot peening) resulted in a fatigue strength reduction of 15-20% in comparison with the mechanically polished surface. The negative effects are likely related to surface damage and relatively high tensile residual stresses in subsurface induced by the heavy peening. Grey cast iron has low ductility in tension and therefore tensile residual stresses may promote multiple cracking and crack networking during cyclic loading.Shot peening using much smaller shots and lower intensity (gentle shot peening) which resulted in a much smaller residual stress field gave no significant changes in fatigue strength. However, a short time annealing at 285°C of specimens being gently shot peened increased the fatigue strength roughly by 10%. The improvement could be an effect of precipitates formed due to the heat treatment, which lock the dislocation movement under cyclic loading.
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