| 1. |
- Johansson, Björn, 1963-
(författare)
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Deciding on Sourcing Option for Hosting of Software Applications in Organisations
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Software applications are of great importance in organisations, and performance of an organisation depends on how hosting of software applications are organised. This thesis deals with the question: Why and how organisations decide on specific sourcing options for software applications hosting. The thesis describes and explains sourcing decision-making processes made in the Swedish Post (MeLo) and Jönköpings Kommun (the municipality). MeLo’s sourcing decision resulted in outsourcing of hosting, and the municipality’s sourcing decision resulted in internal sourcing of hosting. Both organisations were distinguished by a decentralised structure to a great extent and showed a huge diversity in software applications used. The sourcing decisions resulted in a change to a more centralised hosting of software applications. The thesis is a retrospective case study based on semi-structured interviews and documents analysis. Concepts from the resource-based view and factors described in sourcing literature are used to analyse these sourcing decisions. From nine theoretical initial propositions 28 propositions are developed about why and how sourcing decisions are made. From these propositions, relations are described and some conclusions are presented about why and how sourcing decisions are made. The main conclusion is that maturity level regarding software applications usage seems to influences the start, the process as such, and the outcome of a sourcing decision-making process. This is explained as the more mature the organisation is regarding usage of software applications the more proactive decision-makers are in the sourcing decision. It is also identified that involved factors can be either influencing or justifying, and it is found that control of software applications usage influences the start of a sourcing decision to a high extent. The findings suggest that a sourcing decision-making process can be described as an irrational decision process that aims at increasing commitment on an already made decision. The study suggests that the less mature and more decentralised the organisation is the more reactive and the stronger influence the need to increase control over software applications have in a sourcing decision-making process.
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| 2. |
- Nilsson Blom, Marcus, 1980-
(författare)
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Opioidberoende : en studie om beroendevården och det sociala sammanhangets betydelse
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Opioid dependence is highly associated with health problems relating to physical health (infectious diseases) as well as mental health (depression, anxiety, antisocial behavior). In addition, research has found an association between use of opioids and increased risk of premature death as a consequence of overdose or other circumstances, such as suicide. Furthermore, opioid dependent individuals experience a high level of social exclusion and problems with relationships, housing, income and livelihood. Overall, there is a connection between opioid dependence and physical, psychological and social vulnerability as well as premature death.The importance of social cohesion has rarely been the focus in research on opioid dependence. Therefore, there is a need to further explore whether differences in outcomes (medication assisted treatment, mortality and co-morbidity) in addition to individual characteristics, can be derived from social aspects of the opioid dependent individual’s life.The overall aim of the dissertation is to examine individual and social factors among individuals who are dependent on opioids and how they are associated with outcomes relating to: a) medication assisted treatment; and b) mortality and co-morbidity.This dissertation is based on data from four different registers. The first and second sub-studies use ASI data. The third uses DOK data from the National Board of Institutions (SiS) and the Death Registry (National Board of Health and Welfare). The fourth study is based on both DOKdata and data from the national patient registry (National Board of Health and Welfare).Overall, this dissertation confirms the understanding of opioid dependence as associated with a high level of vulnerability. This dissertation shows that opioid dependence is characterized by extensive care efforts, low levels of employment, and a high level of mental health and comorbidity.This dissertation shows that the characteristics related to the social network (parenting, work and education) are of significance for being in treatment, but also remaining in care (medication assisted treatment), which in turn promotes the individual's health and long-term health development. In that, this dissertation shows that for individuals dependent on opioids, there is an association between being part of a social network and favorable health development.
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| 3. |
- Nilsson, Daniel, 1982-
(författare)
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A ΔJ approach for nonlinear fatigue crack propagation : Experimental and numerical investigation of a ductile superalloy
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation is a product of an academic-industrial collaboration between the Division of Solid Mechanics at Linköping University and Siemens Energy AB. The focus is on enhancing the design optimisation procedures for high-temperature components in industrial gas turbines (IGT). The research is centred around the behaviour of the nickelbased high-temperature superalloy Haynes 230 under service-like conditions with predominant thermal loads. The aim is to improve fatigue crack propagation life predictions for nonlinear conditions.The research findings validate the thermal ageing fatigue effects on Haynes 230 as seen in existing literature, especially on constitutive properties and crack initiation. Additionally, it was observed that thermal ageing has a minor effect on the crack growth rate up to 600 °C, which can be managed by updating the crack driving force with thermally aged properties.The project mainly focused on nonlinear crack propagation at isothermal and thermomechanical fatigue conditions. A new method for crack length description, using a modified compliance method, is introduced. This method simplifies and enhances the accuracy of crack length measurements and has become an established method for evaluating the single edge notch specimen used in the project under thermo-mechanical fatigue conditions.The nonlinear fatigue parameter ΔJ was incorporated into both Finite element method (FEM) computations and test evaluations, revealing linear trends with crack growth rates in loglog. The research highlights the crucial role of crack opening in establishing a correlation between ΔJ and crack growth rate. It was also concluded that the linear fatigue fracture parameter ΔK tends to underestimate the crack growth behaviour, resulting in non-conservative outcomes if the elasto-plastic stresses from the tests are considered.Lastly, a constitutive description of Haynes 230, based on the Ohno-Wang theory, under negligible viscoplastic effects, and an extension of the cycle jumping procedure that takes into account the significant hardening between the initial and midlife stages of the material, is presented. By this the notched geometry in 3D could be simulated with satisfying accuracy.
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| 4. |
- Grip, Björn
(författare)
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Den ojämlika dödligheten : Hjärtdödlighet och samhällsutveckling i två städer
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Den ojämlika dödligheten är en studie av främst hjärt–kärldödlighet avseende perioden 1950–2010 i tvillingstäderna Linköping och Norrköping och konsekvenserna av ojämlikhet. Skillnaderna mellan städerna i dödlighet är stora. Under 1970-talet, då jämlikheten stod i focus, minskade dessa. Efterhand som ekonomisk politik och samhällsvärderingar mera anpassades till en global monetaristisk politik ökade också den ojämlika dödligheten mellan städerna.Stora förändringar ägde rum inom respektive stad när det gäller hjärtdödligheten. Miljonprogramområdena i de båda städerna blev relativt sett fattigare och präglades allt mer av flyktinginvandring, samtidigt som städernas centra gentrifierades, inte minst i Linköping. Skillnaderna i dödlighet mellan ytterområdena och centrum ökade under 1990- och 2000-talen. Detta gäller i större utsträckning i Linköping än i Norrköping.Avhandlingen består av tre delar. I licentiatuppsatsen analyseras städernas utveckling från 1950-talet till 2006. Studien gör också ett försök att spåra orsaker till ohälsoskillnader och för tidig död. Artikel 1 handlar om vad som hände med folkhälsan på vägen från ett högindustriellt till ett postindustriellt samhälle. Ett särskilt focus har varit att studera skillnader i hjärtsjuklighet mellan olika stadsdelar i de bägge tvillingstäderna. I artikel 2 analyseras skillnader i hjärt–kärldödlighet på stadsdelsnivå under perioden 1976 till 2010.
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| 5. |
- Hoffman, Tove
(författare)
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Dispersal of ticks and their microorganisms by African-Western Palaearctic migratory birds
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Europe, tick-borne diseases are the most widespread and common vector-borne diseases and their geographical distribution is increasing. The dispersal of ticks depends on the movements of their vertebrate hosts. Avian hosts are more likely to be involved in long-distance range expansion of ticks due to their migration pattern. Billions of birds in the African-Palaearctic migration system migrate biannually between breeding grounds in the Palaearctic and wintering grounds in Africa and thereby create natural links between Africa, Europe, and Asia. In this thesis the dispersal of ticks and their microorganisms by northbound migratory birds utilizing flyways in the African-Western Palaearctic region has been investigated and the association between bird ecology and tick taxon addressed. The results suggest that long-distance migratory birds with wintering regions in Africa are involved in northward dispersal of the tick species Hyalomma rufipes, a known vector or Crimean-Congo hemorrhagic fever virus, and that birds with an open or wetland habitat have more H. rufipes in comparison to birds with a winter habitat comprising forest and shrubs. The results also suggest a role for birds in the ecology of Alkhurma hemorrhagic fever virus, a hemorrhagic flavivirus, and a potential mechanism for dispersal of the virus to new regions, including Europe and Asia Minor. The results did not provide evidence for immature ticks of the Hyalomma marginatum complex and birds having a major role in the ecology and northward dispersal of tick-borne Anaplasma phagocytophilum, a zoonotic bacterium causing febrile illness in humans and domestic animals. However, the results give support to the idea of a divergent enzootic cycle of A. phagocytophilum involving birds as hosts. Finally, the results of this thesis suggest that H. rufipes do not serve as vectors or contribute to the transmission of the tularemia-causing bacterium Francisella tularensis and that migratory birds do not contribute to northward dispersal of F. tularensis-infected ticks. However, the results suggest that migratory birds contribute to northward dispersal of H. rufipes carrying both Francisella and spotted fever group Rickettsia species, including Francisella-like endosymbionts and Rickettsia aeschlimannii. In conclusion, this thesis helps to clarify the knowledge about the dispersal of ticks and the microorganisms they carry by northbound migrating birds in the African-Western Palaearctic region. Furthermore, it highlights the need of establishing surveillance programs for monitoring the risk of introduction and establishment of important exotic tick species, such as H. rufipes, and tick-borne pathogens in the Western Palaearctic.
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| 6. |
- Lindblom, Anders, 1957-
(författare)
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Spotted Fever Rickettsioses in Sweden : Aspects of Epidemiology, Clinical Manifestations and Co-infections
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The spotted fever group rickettsiae are emerging diseases. They cause damage in their hosts by invading the endothelium in small to medium-sized blood vessels, which results in vasculitis that can cause clinical manifestations from most organs.The present thesis describes the prevalence of Rickettsia helvetica in ticks, the incidence of rickettsial infection based on seroreactivity and seroconversion in humans and their symptoms, from different parts of Sweden and the Åland Islands in Finland. This was accomplished through serological analysis of both retrospective and prospective serum samples from confirmed and suspected tick-bitten individuals compared to individuals with no knowledge of tick exposure (blood donors). We found a comparable seroprevalence to Rickettsia spp. in different geographical areas where ticks are present; it was also comparable to the seroprevalence of Borrelia spp. Seroprevalence was also more common, as suspected, in the tick-exposed group compared to blood donors. In comparison with co-infections with other tick-borne infections (Anaplasma spp. and Borrelia spp.), we could conclude that co-infections do exist and that, based on clinical findings, it is difficult to distinguish which microorganism causes certain clinical manifestations. For reliable conclusions regarding the causative microorganism, the diagnosis should basically rely on diagnostic tests. In comparison with Borrelia spp., seroconversion to Rickettisa spp. was more common in the areas we investigated, indicating that rickettsiosis is a common tick-borne infection in Sweden and most likely underdiagnosed.When investigating patients with meningitis, we found R. felis in cerebrospinal fluid from two patients with subacute meningitis. This was the first report in which R. felis was found and diagnosed in patients in Sweden. The patients recovered without sequelae and without causal treatment. To provide guidelines on when to treat Rickettisa spp. infections, more investigations are needed.The present thesis shows that Rickettsia spp. are common in ticks and do infect humans. Rickettsial infection should be considered in both non-specific or specific symptoms after a tick bite. It was also shown in the thesis that flea-borne rickettsiosis (R. felis) occurs in Sweden and may cause invasive infections
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| 7. |
- Nilsson, Micael, 1964-
(författare)
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Genusregim i förändring : Jämställdhet och makt i kommunal politik mellan åren 1970 och 2006
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Det övergripande syftet med denna avhandling är att synliggöra formella och informella maktstrukturer i Norrköpings kommuns politiska ledning mellan åren 1970 och 2006 ur ett genusperspektiv. I inledningen ställs frågan om det är så att kvinnors inlemmande i kommunalpolitiken endast har lett till en jämn könsrepresentation i den politiska toppen, men inte medfört verklig politiskt makt. Utifrån ett samtidshistoriskt perspektiv undersöks den underliggande maktstruktur om den politiska makten i Norrköping kan sägas ha vilat på vid olika tidpunkter mellan 1970 och 2006.Den teoretiska ansatsen är inspirerad av ett feministiskt genusperspektiv och det empiriska materialet analyseras med hjälp av bl a begreppet genusregim. Detta begrepp utgör grunden i avhandlingens teoretiska ram. I den konkreta analysen används sedan begrepp som politisk fält och politiskt kapital, manlighet, manlig homosocialitet, hegemoni och diskursiv makt.Utgångspunkten i avhandlingen är att kvinnor och mäns olika tillgång till informell makt i politiken dels har att göra med makt som baseras på genus, dels har att göra med makt kopplat till relationerna mellan ledande politiker och ledande tjänstemän i kommunens administrativa ledning. Avhandlingen undersöker på vilket sätt kvinnliga och manliga politikers formella deltagande i kommunens nämnder, kommunstyrelsen och andra organ förändrades under perioden 1970–2006. Den belyser också hur politiker och tjänstemän har uppfattat den underliggande maktstruktur som underbygger verklig politisk makt, samt hur denna maktstruktur har förhållit sig till genus. Avhandlingen undersöker även huruvida manliga tjänstemän begränsat kvinnliga politikers maktutrymme.Avhandlingen visar att den makt som underbygger den politiska styrningen har vilat på två slags ordningsrelationer: den mellan kvinnor och män respektive den mellan den politiska ledningen och administrationen. Avhandlingen visar således att problemet med kvinnors brist på informell makt har varit inbyggt i det politiska systemet.
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| 8. |
- Nilsson, Susanna, 1978-
(författare)
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Augmentation in the Wild : User Centered Development and Evaluation of Augmented Reality Applications
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Augmented Reality (AR) technology has, despite many applications in the research domain, not made it to a widespread end user market. The one exception is AR applications for mobile phones. One of the main reasons for this development is technological constraints of the non-mobile phone based systems - the devices used are still neither mobile nor lightweight enough or simply not usable enough. This thesis addresses the latter issue by taking a holistic approach to the development and evaluation of AR applications for both single user and multiple user tasks. The main hypothesis is that in order for substantial wide spread use of AR technology, the applications must be developed with the aim to solve real world problems with the end user and goal in focus.Augmented Reality systems are information systems that merge real and virtual information with the purpose of aiding users in different tasks. An AR system is a general system much like a computer is general; it has potential as a tool for many different purposes in many different situations. The studies in this thesis describe user studies of two different types of AR applications targeting different user groups and different application areas. The first application, described and evaluated, is aimed at giving users instructions for use and assembly of different medical devices. The second application is a study where AR technology has been used as a tool for supporting collaboration between the rescue services, the police and military personnel in a crisis management scenario.Both applications were iteratively developed with end user representatives involved throughout the process and the results illustrate that users both in the context of medical care, and the emergency management domain, are positive towards AR systems as a technology and as a tool in their work related tasks. The main contributions of the thesis are not only the end results of the user studies, but also the methodology used in the studies of this relatively new type of technology. The studies have shown that involving real end users both in the design of the application and in the user task is important for the user experience of the system. Allowing for an iterative design process is also a key point. Although AR technology development is often driven by technological advances rather than user demands, there is room for a more user centered approach, for single user applications as well as for more dynamic and complex multiple user applications.
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| 9. |
- Stawreberg, Lena
(författare)
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Energy Efficiency Improvements of Tumble Dryers : -Technical Development, Laundry Habits and Energy Labelling
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tumble dryers are becoming more and more common in ordinary households as a complement to the washing machine. Tumble dryers offer a fast drying cycle independent on weather conditions and require small space. They do, however, considering the large number of units use a large amount of electricity. The main objective in this thesis is to identify possibilities in order to reach a reduced electricity use for domestic tumble-drying of clothes. This involves an investigation of the condensing tumble dryer in order to point out possible energy efficiency improvements. The purpose of the energy label, which indicates the energy efficiency of the tumble dryer, is also studied, whether it matches the actual laundry habits. Finally, suggestions for technical development of the tumble dryer are made in line with today’s consumer behaviour. The performance of the condensing tumble dryer has been studied using a design of experiments to create a statistical model in Paper I. This model was used to find the best settings for the power supply to the heater, the internal airflow and the external airflow in order to reach a high specific moisture extraction rate (SMER) and a low leakage ratio. A low external airflow and high power supply to the heater gives the highest SMER. To reach the lowest values for the leakage ratio, a low internal airflow should be applied together with a high external airflow. The use of a statistical model gave valuable information of the performance of the existing tumble dryer. For further improving the energy efficiency of the dryer, the amount of leakage and its location was investigated in Paper IV. By studying energy and mass balances from experiments, pressure measurements and modelling, the effects of leakage on the process were evaluated. As the location of the leakage is so important for the energy efficiency, the worst-case scenario where leakage is located between the heater and the drum is used as a start point in the study. It was determined that there is a large leakage of air between the heater and the drum leading to a significant loss in energy recovery. The drying loads used by consumers are getting smaller, often less than 3 kg dry load, while the maximum capacity of the dryers are increasing, up to 7 or 8 kg. In Paper II, tests were made with different loads in order to investigate if the energy label serves its purpose as today’s standard is set at the dryers’ maximum capacity. The results from this study show that the energy efficiency when drying a small load is significantly lower than for a large load. In order to encourage a production of tumble dryers with higher energy efficiency for small loads, where the dryer is most frequently used, the standards for the energy label should be revised. Today, manufacturers do not gain any benefits by improving the performance for partial loads. A mathematical model over a venting tumble dryer was established in Paper III with the aim of testing different control strategies in order to improve the energy efficiency of the tumble dryer for partial loads. The ideas behind the different strategies were to minimize the heat losses during the drying process and to increase the residence time for the air in the drum and thereby increase the moisture content of the air leaving the drum. Using such a control strategy it is possible to reach an improvement of SMER by approximately 4% when drying small loads. In order to reach larger improvements, however, a more extensive product development will be necessary. Finally, the results in this thesis points at the necessity of including not only the technical development of the tumble dryer, but also the policy tools involved and the consumers’ habits in order to reach a reduced electricity use for drying clothes in households.
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| 10. |
- Wallménius, Katarina, 1983-
(författare)
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Studies of Spotted Fever Rickettsia - Distribution, Detection, Diagnosis and Clinical Context : With a Focus on Vectors and Patients in Sweden
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The spotted fever rickettsia, Rickettsia helvetica, is an endemic tick-borne bacteria in Sweden. It causes infections in humans, manifested as aneruptive fever, headache, arthralgia and myalgia, and sometimes an inoculation eschar or a rash. There have also been two known cases of human infections with R. felis in Sweden.The present thesis starts by investigating dispersal of ticks and Rickettsia spp. by migrating birds flying from Africa to Europe. Almost 15,000 birds were searched and 734 ticks collected, mainly of the species Hyalomma marginatum complex. Almost half (48%) of the ticks were infected with Rickettsia spp., 96% of which was R. aeschlimannii, the remaining R. africae and undefined species.The next study focused on questing ticks over a large area in Sweden and determining the prevalence of Rickettsia spp., Anaplasma spp. and Coxiella burnetii. Rickettsia spp. was found in 9.5-9.6% of the ticks and A. phagocytophilum in 0.7%; no C. burnetii was found.The last three papers in the thesis focused on the clinical presentation of rickettsiosis, the symptoms associated with the infection in general and particularly in patients with neurological complications. A tick-exposed population in Sweden was investigated to gain a better understanding of symptoms due to rickettsioses, also in relation to co-infections with other tick-borne bacteria. Based on symptoms, it was not possible to distinguish what pathogen caused the infections. Most patients had erythema migrans, some had serological reactions to Rickettsia spp., Borrelia spp. or co-infections by Rickettsia spp., Borrelia spp. and/or Anaplasma spp. In the fourth and fifth papers, we found associations between antibodies against Rickettsia spp. and sudden deafness (in 10-24% of patients) and facial nerve paralysis (in 8.3-25% of patients). In three patients R. felis was detected in the cerebrospinal fluids. Briefly, the thesis helps to clarify our knowledge about tick dispersal, shows a narrower prevalence estimate of Rickettsia spp. in Swedish ticks, and illuminates symptoms of rickettsioses and co-infections with other tick-borne infections. It also shows that presence of erythema migrans may be explained by more than Lyme disease and indicates a possible association between rickettsiosis and sudden deafness and facial nerve paralysis.
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