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- Iraeus, Johan, 1973-
(författare)
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Stochastic finite element simulations of real life frontal crashes : With emphasis on chest injury mechanisms in near-side oblique loading conditions
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction. Road traffic injuries are the eighth leading cause of death globally and the leading cause of death among young people aged 15-29. Of individuals killed or injured in road traffic injuries, a large group comprises occupants sustaining a thorax injury in frontal crashes. The elderly are particularly at risk, as they are more fragile. The evaluation of the frontal crash performance of new vehicles is normally based on barrier crash tests. Such tests are only representative of a small portion of real-life crashes, but it is not feasible to test vehicles in all real-life conditions. However, the rapid development of computers opens up possibilities for simulating whole populations of real-life crashes using so-called stochastic simulations. This opportunity leads to the aim of this thesis, which is to develop and validate a simplified, parameterized, stochastic vehicle simulation model for the evaluation of passive restraint systems in real-life frontal crashes with regard to rib fracture injuries.Methods. The work was divided into five phases. In phase one, the geometry and properties of a finite element (FE) generic vehicle buck model were developed based on data from 14 vehicles. In the second phase, a human FE model was validated for oblique frontal crashes. This human FE model was then used to represent the vehicle occupant. In the third phase, vehicle buck boundary conditions were derived based on real-life crash data from the National Automotive Sampling System (NASS) and crash test data from the Insurance Institute for Highway Safety. In phase four, a validation reference was developed by creating risk curves for rib fracture in NASS real-life crashes. Next, these risk curves were compared to the risk of rib fractures computed using the generic vehicle buck model. In the final phase, injury mechanisms in nearside oblique frontal crashes were evaluated.Results. In addition to an averaged geometry, parametric distributions for 27 vehicle and boundary condition parameters were developed as guiding properties for the stochastic model. Particular aspects of the boundary conditions such as pulse shape, pulse angle and pulse severity were analyzed in detail. The human FE model validation showed that the kinematics and rib fracture pattern in frontal oblique crashes were acceptable for this study. The validation of the complete FE generic vehicle buck model showed that the model overestimates the risk of rib fractures. However, if the reported under-prediction of rib fractures (50-70%) in the NASS data is accounted for using statistical simulations, the generic vehicle buck model accurately predicts injury risk for senior (70-year-old) occupants. The chest injury mechanisms in nearside oblique frontal crashes were found to be a combination of (I) belt and airbag loading and (II) the chest impacting the side structure. The debut of the second mechanism was found for pulse angles of about 30 degrees.Conclusion. A parameterized FE generic passenger vehicle buck model has been created and validated on a population of real life crashes in terms of rib fracture risk. With the current validation status, this model provides the possibility of developing and evaluating new passive safety systems for fragile senior occupants. Further, an injury mechanism responsible for the increased number of outboard rib fractures seen in small overlap and near-side oblique frontal impacts has been proposed and analyzed.
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- Paulson, Fredrik, 1976-
(författare)
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Inclusion of sustainability aspects in product development at manufacturing companies
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Due to current consumption and production patterns of products, pressure on already constrained natural resources, an increasing global population, increasing concentrations of greenhouse gases in the atmosphere and reduced access to clean water globally, studying manufacturing companies’ inclusion of sustainability aspects in their product development becomes important.The aim of this thesis is to expand current knowledge on the inclusion of sustainability aspects in product development at manufacturing companies. More specifically, the expansion of current knowledge covers how manufacturing companies include sustainability aspects in product development, the challenges manufacturing companies may face when including sustainability aspects in product development, and the reasons for these challenges.To fulfil this aim, a literature study and a multiple case study were conducted at two international, listed, manufacturing companies in Sweden. Empirical data was collected using semi-structured interviews with two employees at each company and by analyzing the companies’ latest sustainability report.Empirical results include two context-dependent descriptions of how manufacturing companies include sustainability aspects in product development, 21 challenges the companies face, and 14 reasons for those challenges.Conclusions include: (1) the role of conventional methods when including sustainability aspects in product development has been largely ignored in prior research; (2) a company’s product owner influences the inclusion of sustainability aspects in product development, and in product requirements in particular; (3) the following three challenges are proposed incorporated in a comprehensive framework of challenges that has been developed in prior research:Making suppliers fulfil the sustainability requirements that are placed on them. Transforming sustainability aspects, or general goals, into measurable requirements that contribute to reduced environmental impact from products while at the same time contributing to competitive profit.Identifying how to reach economic goals more efficiently with a more sustainable initiative or solution than other initiatives.
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3. |
- Szychowska, Malina, 1991-
(författare)
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Effects of visual load on auditory processing
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In daily life, people need to be able to focus on a task while ignoring any task-irrelevant background noise. For example, people who work in an open-space office may have to work on a report while ignoring the background talk among co-workers. Theories of attention argue that processing of task-irrelevant auditory information should become attenuated when attentional capacity is exhausted by task-relevant stimuli, for example a visual task. According to early-filter theory, top-down attenuation of auditory responses is possible at various stages of the auditory pathway through multiple recurrent loops. Furthermore, the adaptive filtering model of selective attention suggests that filtering occurs early when concurrent visual tasks are demanding (e.g., high load) and late when tasks are easy (e.g., low load).The main aim of this thesis was to investigate whether auditory processing is attenuated during concurrent visual load manipulation, and if so, at which stage of the auditory pathway. Recurrent loops that are present throughout the entire auditory pathway should allow top-down modulation of even earliest responses, especially when accompanied by a highly demanding task. Recording these auditory responses during concurrent visual tasks with different levels of load could potentially show at which stages of auditory processing the filtering happens when the task demands are high or low, or there is no task at all.This thesis tested the effects of visual load manipulation on the responses originating from different stages of the auditory pathway: mismatch negativity (MMN) to duration in Study I, MMN to frequency in Study III, auditory steady-state responses (ASSRs) to a 40-Hz modulation frequency in Study IV, and ASSRs to 20-, 40-, and 80-Hz modulation frequencies in Study V. Additionally, Study II compared different control conditions (cascade vs. no-repetition control) for evoking MMN to find a design that reduces confounds in the MMN. Results of Study II showed that cascade and no-repetition control are comparable control conditions for evoking MMN.For the effects of visual load manipulation on auditory MMN (low vs. high load), results showed moderate evidence for the effect of load on duration MMN and moderate evidence for no effect of load on frequency MMN. However, results for the duration MMN might be confounded by physical differences between the low load and high load conditions in the visual task, and by a biased oddball paradigm used to evoke the MMN. Thus, it is most likely that auditory MMN is not affected by visual load (low vs. high).For the effects of visual load on ASSRs (no, low, and high load), results showed moderate to strong evidence for no effects of load manipulation on ASSRs, but some comparisons were inconclusive. The convincing evidence obtained in Studies IV and V points to the robustness of ASSRs against visual load manipulation.Because it is most likely that neither MMN nor ASSRs are affected by visual load manipulation, results presented in this thesis support the idea that attentional resources are modality specific. Because it is possible that filtering occurs at one stage of auditory processing and does not change with the concurrent task demands, the present results do not rule out the early-filter theory. However, results are inconsistent with the adaptive filtering model because filtering of task-irrelevant responses does not vary with the demands of the concurrent task.
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- Al-Adhami, Maissa, 1972-
(författare)
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Health of refugee migrants in the early post-migration phase in Sweden : The role of health resources and health promotion
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the early post-migration phase, the health and well-being of newly settled refugee migrants is negatively affected by structural factors such as restrictive immigration policies, hostile political discourse and limited housing and work opportunities. There is a need for a better understanding of how individual health resources and health promotion can mitigate the impact of these ongoing stressors. The thesis aimed to explore, assess, and further the understanding of the role of health promotion and individual health resources for health and well-being of newly settled refugee migrants in Sweden.In Study I, six focus group discussions were conducted with 32 newly settled refugees, exploring their perceptions of a Swedish Civic Orientation (CO) course with added health communication. The results showed that the course inspired them to focus on their health, promoted independence and empowerment, and gave new social contacts. However, the course is needed earlier in the post-migration phase and should be adjusted to better fit refugee migrants’ varying pre-existing knowledge. Study II was a cross-sectional study, exploring how individual resources of newly settled refugee migrants (n=787) were associated with self-rated health and psychological well-being. Logistical regression analysis showed that limited health literacy, lack of emotional support, and low self-efficacy were consistently associated with poor health outcomes. In Study III, interviews with 10 civic communicators were performed to explore their perceptions of an in-depth training course on mental health in relation to observed psychological needs among newly settled refugee migrants. The overall result was that the attainment of new knowledge and new tools enabled them to lead reflective conversations about mental health with participants. Mental health needs were perceived to be related to pre- and post-migration experiences. Barriers included stigma and lack of arenas to address mental health needs of refugee migrants.In Study IV, the effectiveness of a regular and an extended CO course was compared in a quasi-experimental study design among newly settled refugee migrants (n=173 and 143 respectively). Linear mixed models and Chi-square analyses showed that the extended course led to a small, but significant increase in health literacy. No significant differences were observed regarding other outcomes (emotional and practical support, general self-rated health, or psychological well-being).The thesis illustrates the potential of early health promotion initiatives focusing on individual health resources to enhance health. However, overarching structural barriers related to living conditions, work opportunities and inclusion must also be addressed.
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6. |
- Andersson, David E.
(författare)
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The Emergence of Markets for Technology : Patent Transfers and Patenting in Sweden, 1819–1914
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is concerned with the emergence of markets for technology and studies the evolution of patent transfers and its determinants, patent agencies and independent versus firm patenting in Sweden during the 19th century and the turn of 20th century. It explores how and why markets for technology emerge and under what circumstances by investigating the evolution of Swedish patent legislation and the patterns of patent transfers between individuals and firms. It presents a three-pronged framework studying: structure and actors, technology and transactions.Using a new and unique database covering every Swedish privilege and patent over the 1819–1914 period the empirical analysis reveals that although the transferability of intellectual property goes all the way back to the 18th century patent transfers did not start to increase significantly until the first modern Swedish patent law was passed in 1884. Along with the new law a market for patenting services also emerged where actors such as patent agents and the firms they founded, patent agencies, functioned as intermediaries in the market for patents and international networks of patenting. A few older patent agencies managed to create an oligopolistic setting where they introduced price controls through special interest groups.The thesis also questions the current dichotomous classification of independent and firm patenting. The methodological contribution lies in showing that research that depend too much on patent statistics run the risk of underestimating the importance of the firm when patents granted to individuals actually cover inventive activities that has taken place inside the boundaries of firms.Finally, the study shows that special marketplaces for the sale of patented and unpatented technology were created to help inventors find buyers and financiers for their invention and to help firms find new technology. The patent law of 1884 made it possible to trade in several submarkets of technology where the right to patent a certain invention could be bought, ideas could be financed, pending patent applications or the priority right to foreign markets could be bought and sold.The results lend support to the research emphasizing the role of intellectual property as a disclosure and diffusion mechanism for new technology.
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7. |
- Cornell Kärnekull, Stina, 1985-
(författare)
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Auditory and Olfactory Abilities in Blind and Sighted Individuals : More Similarities than Differences
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Blind individuals face various challenges in everyday life because of the lack of visual input. However, since they need to rely on the non-visual senses for everyday tasks, for instance, when navigating the environment, the question has been raised as to whether perceptual and cognitive abilities in these senses may be enhanced. This question has mainly been addressed for auditory and tactile abilities, whereas there is considerably less research into the chemical senses, such as olfaction. However, to determine whether blindness has general effects, different senses and types of tasks should be studied, preferably in one and the same study. Therefore, throughout this thesis, analogous auditory and olfactory tasks that varied in cognitive complexity were studied. In Study I, absolute thresholds, discrimination, identification, episodic recognition (i.e., after a short retention interval), metacognition, and self-reported imagery ability were assessed in early blind, late blind, and sighted participants. The only objective measure on which the blind and sighted clearly differed was the auditory episodic recognition task. The fact that early blind but not late blind participants displayed better memory than the sighted suggested that the onset age of blindness may be important for whether this ability becomes enhanced following blindness. Furthermore, the early blind participants rated their auditory imagery ability higher than the sighted, whereas both early and late blind participants rated their olfactory imagery ability higher than the sighted. In Study II, the participants from Study I were followed up after more than a year and retested on auditory and olfactory episodic recognition and identification. This time, the early blind displayed no advantage over the sighted, suggesting that the influence of blindness on auditory memory may be modulated by the length of the retention interval. Moreover, in line with Study I, identification of sounds and odors was similar in the three groups. In Study III, early blind and sighted participants were examined for potential differences in autobiographical memory as evoked by sounds and odors, respectively. Blindness did not influence the reminiscence bumps (i.e., memory peaks in certain age intervals) or have any clear impact on the number of retrieved sound- or odor-evoked memories. Taken together, the present findings indicate that blindness has no general influence across tasks or sensory modalities. Rather, specific auditory abilities, such as episodic memory, may be enhanced in blind individuals, although such effects may depend on both the onset age of blindness and the length of the retention interval. In conclusion, for most perceptual and cognitive abilities examined, performance seemed unaffected by blindness.
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8. |
- Eklund, Magnus, 1976-
(författare)
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Adoption of the Innovation System Concept in Sweden
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In 2001 Sweden founded the government agency of VINNOVA, named after the OECD-endorsed innovation system concept. Criticising the common assumption that countries are passive and uncritical recipients of the approaches promoted by the OECD, this dissertation tries to show that Swedish actors were in fact very active and strategic as they contributed to the national adoption of the concept. With inspiration from conceptual history and Quentin Skinner’s analysis of the rhetorical use of concepts, this study focuses on the research funding reform process between 1995 and 2001, investigating how actors trying to defend the contested institution of sectoral research used the innovation system concept to rhetorically legitimise their project. To compare these uses with earlier ways of discussing innovation in Sweden, the innovation debate that arose in relation to the industrial crises of the 1970s and 1990s has also been studied. It was found that the early Swedish innovation debate had paid little attention to the university sector. When Research 2000 in 1998 proposed that researcher-dominated research councils should be given control over sectoral research funding, a coalition in favour of industrially relevant research mobilised to protect its influence over research funding. The concept was now appropriated and used to rhetorically reframe the universities as part of a system with the main function of promoting innovations. By using the concept it was also possible to draw on the legitimacy offered by the OECD and science.
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10. |
- Furusten, Kristina, 1965-
(författare)
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Det förändrade kontraktet : Banker och företagskonkurser under 1990-talets finanskris
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During the first years of the 1990s Sweden experienced a severe financial crisis. Many companies and banks in Sweden were in financial distress. In 1992, the number of bankruptcies was the highest in Swedish history and the financial system was headed towards a total break down. Several Swedish banks were forced to accept governmental support in order to avoid bankruptcy, and were at the same time publicly criticised for driving companies into bankruptcy through unexpected termination of credit contracts and demands for additional security. Bank ethics were highly questioned. This thesis discusses what happens to the implicit and explicit contracts between banks and their customers when both parties are in financial distress. According to the traditional principal-agent theory, as principals, banks are supposed to monitor their customers, the agents, in order to ensure that the agents fulfil their loan agreements and repay their debts to the banks. The agents are assumed to behave opportunistically to the detriment of the banks. During a period of deep financial crisis for the Swedish banks, there was, however, reason to believe that the banks may have acted opportunistically to the detriment of the customers. The major findings of this thesis show that the banks broke the implicit contracts and activated the explicit contracts to a greater extent during the financial crisis. This indicates that the banks’ relationship with the customer became more formal, and branch managers and local loan officers became more closely tied to internal rules during and following the financial crisis than before the crisis. The major conclusion of the thesis is that when the principal, in this case the bank, experiences a period of crisis, implicit contracts are likely to be neglected and explicit contracts activated due to increased external pressure on the bank to change its procedures. The principal can thus be expected to behave more opportunistically in order to disassociate itself from previous standard operating procedures found to be illegitimate, at the same time as individual branch managers and loan officers can be expected to behave opportunistically and terminate loan agreements in order to evade personal responsibility for possible future credit losses.
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