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  • 1.
    Shevtsov, Stepan
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för datavetenskap och medieteknik (DM). KU Leuven, Belgium.
    A Control-theoretic Approach to Realize Self-adaptive Software Systems with Guarantees2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Engineering modern software systems is a challenging task as these systems are subject to different types of uncertainties. Examples of such uncertainties are disturbances in the environment that are difficult to predict and goals that may change during operation. The idea of self-adaptation is to handle these uncertainties at runtime, when the knowledge becomes available to resolve them. As more software systems with strict requirements are designed to be self-adaptive, the need for adaptation guarantees is becoming a high-priority concern. Providing such guarantees with traditional architecture-based approaches has shown to be challenging, calling for new approaches to engineer self-adaptive systems. To tackle this challenge, this thesis studies control-based software adaptation (CBSA). CBSA applies principles from control theory to design self-adaptive software systems. More specifically, we address the following research problem using CBSA: how to realize self-adaptive software systems that satisfy multiple stakeholder requirements with guarantees in the presence of uncertainties.

    The thesis addresses the research problem in two subsequent stages. The first stage focuses on satisfying multiple stakeholder requirements of different types, and providing adaptation guarantees. This stage starts with a systematic literature review of CBSA, which provides a comprehensive overview of the field, including existing CBSA approaches, applied models and controllers, and analyzed guarantees. From the review, we identify a number of gaps in the existing research and concrete challenges in addressing the research problem. Then, we devise SimCA, a control-theoretic approach to realize self-adaptive software systems that satisfy multiple requirements with guarantees. SimCA combines mathematical models of software system, a control-based adaptation mechanism, and formal analysis of the required guarantees. SimCA is also reusable, meaning that it can be applied to a family of cooperative software systems with strict requirements. The second research stage focuses on handling different types of uncertainty.We first discuss the types of uncertainty and study whether existing CBSA approaches try to deal with these types. We then introduce an enhanced approach called SimCA* that includes components to deal with uncertainty in software parameters, addition or removal of requirements at runtime and software component interactions. In order to obtain evidence about the applicability and reusability of SimCA and SimCA*, we apply informal exploratory case studies with three software systems with strict requirements from different domains.

  • 2.
    Sjökvist, Tinh
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för skog och träteknik (SOT).
    Coated Norway Spruce: Influence of Wood Characteristics on Water Sorption and Coating Durability2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Wood used outdoors is often degraded and discoloured by microorganisms as a natural part of its life cycle, particularly when exposed to high levels of moisture for prolonged times. In this case, the application of a coating (i.e. paint) is an option for increasing the service life of the wood.

    Norway spruce (Picea abies (L.) Karst.) is commonly used for outdoor applications in Sweden. Earlier studies have shown that uncoated spruce heartwood is less prone to moisture sorption in outdoor exposure, resulting in lower moisture content (MC) levels, as compared to sapwood. However, studies related to the above mentioned characteristics are rather limited for coated spruce, especially including the influence of outdoor exposure (i.e. weathering).

    The aim of this thesis is, therefore, to increase the knowledge of how heartwood and sapwood of different densities influence on the durability of coated Norway spruce for outdoor use. Different types of coatings with alkyd-, acrylic-, flour- (calcimine paint), or linseed-oil-based resin were included. The objectives were to study the water sorption (including MC variation) behaviour and crack formation of uncoated and coated heartwood and sapwood of different densities.

    Furthermore was an objective to study the microbial growth on the surface of similar samples of coated spruce in outdoor exposure. The used methods included wetting and liquid permeability experiments, accelerated water absorption (with samples floating freely in water), and outdoor field test. The field method lasted between three to five years and involved monitoring of the MC variation, the crack formation and the microbial growth on the samples.

    The results based on wetting measurements using octane as the adsorbed liquid showed no difference in liquid permeability between the spruce heartwood and sapwood samples of comparable densities, and indicated a similar level of pit aspiration (closure). The common flow path between two cells of conifers occurs through the pits. Still, the sapwood samples had in general a clearly higher water sorption rate than heartwood samples. It could be concluded that the increased sorption was presumably caused by a lowered water surface tension, most likely by a contamination effect of the water by surface-active sapwood extractives rather than differences in morphology of heartwood and sapwood.

    However, no clear difference in water absorption and MC levels was seen between coated heartwood and sapwood in the field study or in the accelerated water absorption study. Thus, it is suggested that a coating hinders the surfaceactive extractives to lower the water surface tension, resulting in a similar water absorption behaviour of coated heartwood and sapwood. The influence of density on water sorption of coated spruce was similarly to uncoated spruce, meaning the low-density samples had a higher MC than the high-density samples in the field tests. Furthermore, a one-year weathering of the coated and uncoated samples caused a larger increase in water sorption of high-density heartwood in the accelerated water absorption study.

    The field study on uncoated and calcimine-coated spruce showed a higher number of cracks on the high-density samples than on the low-density samples. Additionally, within each density group, a larger number of cracks were seen on sapwood samples as compared to heartwood samples. High-density samples with an alkyd- or an acrylic coating also showed a higher number of cracks. As expected, the formation of cracks on the samples increased their water sorption significantly. The microbial growth was higher on sapwood than on heartwood samples with a white coloured alkyd coating.

    The main conclusion is that heartwood and sapwood of different densities influence the water sorption and durability of coated Norway spruce. However, the principles in water sorption of uncoated heartwood and sapwood could not be applied to coated samples. Overall, the results point out that low-density heartwood could be the best material combination to improve the durability of coated spruce in outdoor use. The knowledge acquired in this thesis can enable an increased service life of coated spruce in outdoor use. The increase in service life is achieved by a careful selection of the wood material regarding the proportion of heartwood and to the choice of wood density. As a concluding remark, the role of surface-active spruce extractives needs to be explored, and a follow-up investigation in the context of water sorption is suggested for future research.

  • 3.
    Jonsdottir, Sigridur Sia
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för hälso- och vårdvetenskap (HV).
    Effects of perinatal distress, satisfaction in partner relationship and social support on pregnancy and outcome of childbirth2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Aim: The aim of this thesis was to achieve a deeper understanding of the situation among women experiencing perinatal distress during pregnancy and childbirth and the effects that dissatisfaction in partner relationship and weak social support from family and friends could have on pregnancy and childbirth.

    Methods: Following screening for perinatal distress, 562 expecting mothers came for a semi-structured interview. This screening, done with the Depression Anxiety Stress Scales and the Edinburgh Postpartum Depression Scale, categorized 360 (64.1%) women into the perinatal distressed group (PDG) and 202 (35.9%) into the non-distressed group (NDG). During the interview women answered the Dyadic Adjustment Scale and the Multidimensional Scale of Perceived Social Support. Data were collected with these instruments for study I. Additional data for the three other studies were gathered from the women´s pregnancy records (II), electronic medical records (II, III), and childbirth records (IV). Results of the four studies were obtained by using descriptive statistics; parametric and nonparametric statistics and regression modeling.

    Results: Women in the PDG were significantly more likely than the NDG to be dissatisfied in their partner relationship, continue smoking during pregnancy, be dissatisfied with division of household tasks and child-rearing, have elementary or lower education, and to be students or unemployed. They were also significantly more likely to experience fatigue, vomiting and pelvic girdle pain during pregnancy. Women in the PDG who received weak family support reported nausea and heartburn more frequently than those with strong family support. Women in the PDG utilized more antenatal care service and were allocated more part time as well as earlier sick leaves during pregnancy, than those in the NDG. Women in the PDG were significantly more likely to use epidural anesthesia as a single pain management during labor.

    Conclusion: Perinatal distress affects pregnancy and childbirth. It is more common among women who are dissatisfied in their partner relationship and with the division of household tasks and child-rearing. Perception of weak social support also affects pregnancy among distressed women. Distressed women along with their partners and families should be offered support and consultation to relieve distress and strengthen their bonds during pregnancy and childbirth.  

  • 4.
    Ulan, Maria
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för datavetenskap och medieteknik (DM).
    Foundation of Multi-Criteria Quality Scoring2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Software quality becomes more critical as our dependence on software increases. We need better quality assessment than ever. Comparison and ranking of software artifacts, detection of bad or good quality are important tasks for quality assessment.

    Software quality models are widely used to support quality assessment. In general, they have a hierarchical structure and defines quality in terms of sub-qualities and metrics in a tree-like structure. Different metrics evaluate different quality criteria, and several metrics often needs to be assessed and aggregated to obtain a total quality score. The quality models standards of today do not enable numerical metrics aggregation. They leave aggregation to decision makers, and different methods of aggregation lead to different assessment results and interpretations. Hence, there is a need to define metrics aggregation formally based on well-known theories.

    We propose to consider the probabilistic nature of quality as a solution. We consider metrics as random variables and define quality scores based on joint probabilities. The aggregation, and the quality model in extension, express quality as the probability of detecting something with equal or worse quality, based on all software projects observed; good and bad quality is expressed in terms of lower and higher probabilities. We analyze metrics dependencies using Bayesian networks and define quality models as directed acyclic graphs. Nodes correspond to metrics, and edges indicate dependencies. We propose an implementation using multi-threading to improve the efficiency of joint probabilities computations.

    We validate our approach theoretically and in an empirical study on software quality assessment of approximately 100\,000 real-world software artifacts with approximately 4\,000\,000 measurements in total. The results show that our approach gives likely results and scales in performance to large projects.

    We also applied our approach to a multi-criteria decision-making task to propose a ranking method to aid evaluation processes. We use a real-world funding allocation problem for a call that attracted approximately 600 applications to evaluate our approach. We compared our approach with the traditional weighted sum aggregation model and found that ranks are similar between the two methods, but our approach provides a more sound basis for a fair assessment.

    Further, we implemented an exploratory multivariate data visualization tool, which visualizes the similarities between software artifacts based on joint distributions. We illustrate the usability of our tool with two case studies of real-world examples: a set of technical documents and an open source project written in Java.

    Our overall results show that our approach for multi-criteria quality scoring is well-defined, has a clear interpretation, and is applicable under realistic conditions, generalizable, and transferable to other domains.

  • 5.
    Zimmer, Björn
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för datavetenskap och medieteknik (DM).
    Guided Interaction and Collaborative Exploration in Heterogeneous Network Visualizations2019Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    The visual exploration of large and complex network structures remains a challenge for many application fields, such as systems biology or social sciences. Often, various domain experts would like to work together to improve the analysis time or the quality of the analysis results. Collaborative visualization tools can facilitate the analysis process in such situations. Moreover, a growing number of real world networks are multivariate and often interconnected with each other. Entities in a network may have relationships with elements of other related data sets, which do not necessarily have to be networks themselves, and these relationships may be defined by attributes that can vary greatly. A challenge is to correctly assign the attributes and relations between different data sets and graphs in order to be able to analyze them visually afterwards. The navigation between the resulting visualizations is also difficult. How can users be guided to other interesting data points relevant to their current view and how can this information be additionally displayed in a graph without losing the overview of the data?

    In this dissertation, we propose our new web-based visualization environment OnGraX, which supports distributed, synchronous and asynchronous collaboration of networks and related multivariate data sets. In addition to standard collaboration features like event tracking or synchronizing, our client/server-based system provides a rich set of visualization and interaction techniques for better navigation and overview of the input network. Changes made by specific analysts or even just visited network elements can be highlighted by heat maps, which enable us to visualize user behavior data without affecting the original graph visualization. We evaluate the usability of the heat map approach against two alternatives in a user experiment.

    Additional features of OnGraX include a comprehensive visual analytics approach that supports researchers to specify and subsequently explore attribute-based relationships across networks, text documents, and derived secondary data. Our approach provides an individual search functionality based on keywords and semantically similar terms over an entire text corpus to find related network nodes. For examining these nodes in the interconnected network views, we introduce a new interaction technique, called Hub2Go, which facilitates the navigation by guiding the user to the information of interest. To showcase these features, we use a large text corpus collected from papers listed in the IEEE VIS publications data set (1990--2015) that consists of 2,752 documents. We analyze relationships between various heterogeneous networks, a Bag-of-Words index, and a word similarity matrix, all derived from the initial corpus and metadata. We also propose a design for the interactive specification of degree-of-interest functions, which can be used to provide and evaluate configurations for guidance based on network attributes and logged user data in heterogeneous networks.

  • 6.
    Lindblad, Fredrik
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för maskinteknik (MT).
    Identifying drivers and barriers for market growth within the industry producing wooden multi-family houses: Land allocation process for future growth2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Sverige är just nu inne i en bostadskris som enligt de svenska myndigheterna förväntas fortsätta fram till 2025. Tillverkare av flerfamiljshus i trä har en relativt liten marknadsandel jämfört med de traditionella byggnadsmaterialen. Den begränsade byggkapaciteten av träbyggnation hindrar även möjligheterna till innovation, bioekonomi och hållbarhet med fokus på miljömässiga och hållbara byggnadsmetoder.

     

    Svenska kommuner ansvarar för att planera en lämplig bostadsutveckling som bygger på krav och strategier i relation till bostadsförsörjningsplanen. Komplexiteten ökar när man kombinerar den ökade efterfrågan med en önskan att utveckla hållbara byggnadslösningar baserade på trä, vilket för närvarande uppnås genom offentlig upphandling eller markanvisning beroende på kommunens utvecklingsstrategi. Detta kan även inkludera lokala strategier beträffande t.ex. design, materialval och geografisk utveckling. Genom att analysera industrins drivkrafter och barriärer kan förbättringsfaktorer identifieras och kunskap om dessa kan bidra till en marknadsutveckling av träbyggnation relaterat till kommunernas behov av bostadsförsörjning. En ökad tydlighet medför förbättrade möjligheter för företag att framgångsrikt svara på kommunernas förfrågan gällande bostadsutvecklingsprojekt. Denna kunskap kan även användas av företagen, regeringen och kommunerna för att bättre förstå det strategiska utvecklingsbehovet relaterat till hållbart byggande av flerfamiljshus med trästomme.

     

    Resultaten i denna avhandling visar att industrin upplever hinder som hör samman med kommunernas agerande och dess kunskapsnivå avseende till träbyggnadslösningar. Den nuvarande marknadsdominans för betong som byggmaterial är ett problem då kommunerna ofta tenderar att välja välkända lösningar. Industrin upplever att kunskapsnivån bland de kommuner som hanterarar markanvisningar är otillräcklig, med subjektiva bedömningar av de presenterade byggnadslösningarna, samt kombinerat med otydliga roller inom markanvisningsprocessen. Dessa faktorer bidrar till osäkerhet och suboptimering för de byggherrar som föreslår en bygglösning baserat på trä.

  • 7.
    Fonseca, Lars
    et al.
    Linnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för pedagogik och lärande (PEL).
    Gerrevall, PerLinnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för didaktik och lärares praktik (DLP). Linnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för idrottsvetenskap (ID).Gustafsson, BarbroLinnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för didaktik och lärares praktik (DLP).
    Lämplighetsbedömning inför antagning till lärarutbildningen: Erfarenheter från Linnéuniversitetets försöksverksamhet2019Samlingsverk (redaktörskap) (Övrigt vetenskapligt)
  • 8.
    Ehriander, Helene
    Linnéuniversitetet, Fakulteten för konst och humaniora (FKH), Institutionen för film och litteratur (IFL).
    Möten: Texter från Linnéuniversitetets kurs Att skriva barnlitteratur 2018-20192019Samlingsverk (redaktörskap) (Övrig (populärvetenskap, debatt, mm))
  • 9.
    Sjöstrand Öhrfelt, Magdalena
    Linnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för didaktik och lärares praktik (DLP).
    Ord och inga visor: konstruktioner av förskolebarnet i kunskapsekonomin2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Historically, changes in preschool policy have been legitimized in relation to ideas about the preschool child and the various problems that the education of this child is supposed to be able to “solve”. From an early age, children have been considered the most effective tool for dealing with a variety of social, economic or environmental issues of central importance for maintaining and developing society.

    Against this background, the purpose of this thesis is to examine representations of the preschool child in different policy texts (textbooks, research- and educational policy) related to changing requirements and targets affecting contemporary Swedish preschools. Discursive constructions of the preschool child are considered as important central aspects, used to legitimize political reforms in accordance with pedagogical ideas and prevailing social contexts. The thesis focuses on the tensions within contemporary constructions of the preschool child in the so-called “knowledge economy”: i.e. the tensions between a competent child, who is both able and willing to take advantage of education, and a “newcomer” – the vulnerable child – in need of obtaining the benefits of education in order to be able to cope with the future.

    The simultaneously competent and vulnerable preschool child is thus an efficiently designed target for the interests of economic transnational organizations viewing education mainly in terms of human capital development, as well as an important factor for economic competitiveness.

    In the thesis’ final analysis, I study how the OECD, EU and IEA are developing methods for measuring and evaluating the results of preschool education, with the intention of being able to "streamline" it by finding universally successful concepts that are both cost-effective and of high quality. The construction of the preschool child as simultaneously competent and vulnerable is used to legitimize shifts in power over the definition of the Swedish preschool agenda, the fundamental ideas of what preschool is about, what its aims are, and for whom it is intended. As these ideas are disguised as being the result of supposedly "objective" forces far from the ideological contradictions of the political sphere, a critical discussion concerning the goals and aims of early childhood education becomes almost impossible to achieve.

  • 10.
    Thulin, Johanna
    Linnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för socialt arbete (SA).
    Putting words to child physical abuse: Possible consequences, the process of disclosure, and effects of treatment. From children’s perspectives2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Aim: The overall aim of the thesis is to explore the experiences and possible consequences concerning reported health and relations between a parent perpetrator of physical child abuse and the children who are victims of the parental physical abuse, the children’s thoughts when disclosing the abuse, and the impact of an intervention designed to support these children in a Swedish context – Combined Parent Child Cognitive Behavioral Therapy (CPC-CBT). Methods: This thesis has a mix-method design. Study I and IV used different self-assessment scales, and the outcomes were analysed using descriptive statistics, paired-samples t test, independent t test, ANOVA, Pearson correlations, and hierarchical linear regression. Study II and III consisted of interviews with 15 (Study II) and 20 (Study III) children, respectively. The interviews were transcribed verbatim and analysed using qualitative content analysis. Results: The results suggest that experiencing child physical abuse affects the relationship between a parent and a child as well as the child’s wellbeing in several ways. However, the results also suggest that participating in the CPC-CBT intervention could decrease parents’ use of violence and increase the child’s wellbeing. In addition, the results suggest that trust and participation influence whether a child discloses abuse and contributes to the success of treatment. Conclusion: The CPC-CBT could be seen as a successful turning point for the participating children, shifting from one trajectory (living in fear of violence) to another (living without fear). Furthermore, when children disclose to adults about their physical abuse, it is important that the adults recognise the children’s participatory rights and strive to earn their trust.

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