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The aim of this work is to optimize the acoustic nondestructive method (NDT) Impact-Echo (IE) as a complementary diagnostic tool for the assessment of concrete structures exposed to high temperatures. Commonly used diagnostic procedures for concrete structures affected by fire are most often limited to in-situ core drilling and subsequent testing of the drilled holes by destructive testing. The Impact-Echo method allows non-destructive testing of variously degraded test specimens and concrete structures, but its use for the assessment of temperature-degraded cementitious composites is hardly ever used in practice. Many studies suggest that Impact-Echo is one of the most suitable non-destructive methods for assessing the rate of degradation by elevated temperature. The dissertation work consists of three main stages, where the first stage is devoted to the production of test specimens of different mixtures and their subsequent degradation by elevated temperature and testing by the IE method and by reference destructive and non-destructive methods. The second stage consists of manufacturing a reinforced concrete element with built-in thermocouples and its subsequent inhomogeneous degradation by a local source of elevated temperature. The controlled degraded element thus prepared contains all grades of thermally degraded concrete tested in the first stage. Subsequent testing consists of verification of standard procedures in the field of acoustic NDT with simultaneous use of experimental modal analysis. In the third stage, the objective is to interpret the measured data from both previous parts, to verify whether within the closed element temperature-degraded areas can be distinguished from one another, or the degree of thermal degradation of concrete. Based on these results, the optimal testing procedure was determined and the basic assumptions for the creation of degrees of damage of the concrete by increased temperature were determined.

This master’s thesis deals with conditions and procedures of testing network echo cancellers according to recommendation ITU-T G.168. The point of it’s interest is design of test application which will perform the objective testing their basic and extended features in MATLAB. Theoretical section is concentrated on declaration the ground of echo cancellers and conditions of their testing. Procedures of particular tests follow in next part. The last section designs the testing function which results in entire application which tests submitted canceller and in chosen file write out the report and is also able to display results like graph.

Master´s thesis „Echocardiographic interactive atlas of basic cardiovascular diseases“, deals with new Biomedical cathegory – clinical engineering (which includes diagnostics and image analysis). It deals with basic learning tools for this not well known specialization.

This doctoral thesis proposes a new algorithm for the reconstruction of impedance images in monitored objects. The algorithm eliminates the spatial resolution problems present in existing reconstruction methods, and, with respect to the monitored objects, it exploits both the partial knowledge of configuration and the material composition. The discussed novel method is designed to recognize certain significant fields of interest, such as material defects or blood clots and tumors in biological images. The actual reconstruction process comprises two phases; while the former stage is focused on industry-related images, with the aim to detect defects in conductive materials, the latter one concentrates on biomedical applications. The thesis also presents a description of the numerical model used to test the algorithm. The testing procedure was centred on the resulting impedivity value, influence of the regularization parameter, initial value of the numerical model impedivity, and effect exerted by noise on the voltage electrodes upon the overall reconstruction results. Another issue analyzed herein is the possibility of reconstructing impedance images from components of the magnetic flux density measured outside the investigated object. The given magnetic field is generated by a current passing through the object. The created algorithm for the reconstruction of impedance images is modeled on the proposed algorithm for EIT-based reconstruction of impedance images from voltage. The algoritm was tested for stability, influence of the regularization parameter, and initial conductivity. From the general perspective, the thesis describes the methodology for both magnetic field measurement via NMR and processing of the obtained data.

Purpose – At the beginning of this year the number of social media user worldwide was recorded to be at 3.80 billion and is estimated to keep rising (Kemp, 2020). Along with this connectivity, new concepts have been acknowledged that have caused some controversy. These concepts have been named echo chambers and filter bubbles. This study investigates how social media users experience personalisation algorithms and the perceived existence of filter bubbles and echo chambers on various social media platforms and channels. Furthermore, it explores to what extent these users make use of strategies when navigating their social media feeds and if they believe that said strategies have any effect on personalisation algorithms, filter bubbles, and echo chambers. Method – Semi-structured interviews were conducted with 10 participants currently studying at Jönköping University. The interviews were then transcribed and analysed using a thematic approach.  Findings – The perception of students at Jönköping University is that filter bubbles and echo chambers exist in a varying degree of visibility and commonality depending on the situation and medium. These are also experienced to be interconnected with personalisation algorithms. The experience of personalisation algorithms is mainly positive, as it allows the users to easily navigate the feed but negative implications are also mentioned.  These are isolation, the negative strengthening and creation of filter bubbles or echo chambers. However, the algorithm is not believed to be the only thing responsible for the creation. The users believe that their own navigation and strategies can have such an effect. The strategies that users use are (1) Passive navigation, (2) Source evaluation, (3) Multiple source searching, (4) Responsibility taking, and the (5) Creation of filter bubbles. The effect these have on filter bubbles, personalisation algorithms and echo chambers is helping, to an extent, alleviate some of the negative effects that these are experienced to have. However, the passive navigation and creation of filter bubbles have a somewhat opposite effect as they help the creation or maintaining of filter bubbles and personalisation algorithms. Implications – The findings in this study build on existing evidence of echo chambers being more easily formed when the topic of discussion is of a political nature, as it is described by Barberá, Jost, Nagler, Tucker, and Bonneau (2015) in their research on how echo chambers form on Twitter. Furthermore, these findings could be considered to disagree with the research of Dubois and Blank (2018) who found that people who had a high political interest were less likely of ending up in an echo chamber. Although, due to their research taking all media into account, such as television, radio, newspaper, and so forth, while the current study is focused on social media alone the comparison is a bit more difficult to make. Finally, in the study made by Seargeant and Tagg (2019), it was concluded that the personalisation algorithms are not the sole contributor to filter bubbles forming on Facebook and that the users play a key role in how their online environment is shaped. The results of this study build on their research that the users do use strategies when navigating that affect what is being shown to them on their social media feeds. However, the participants of the current study claimed that the algorithms played a pretty large role too, which is not quite in line with the research conducted by Seargeant and Tagg (2019). Limitations – The generalisability of this study is limited due to the small sample size chosen to conduct this study, although instead, it provides deeper insight into the relationship between humans and their social media platforms and channels. Moreover, a bias that should be acknowledged is that when conducting interviews there is a risk of encountering response bias, which is when the participants assume the purpose of the study and adapt their answers to fit what they believe the researcher(s) want to hear. To avoid this precautions were taken when designing the questions to make sure that they would not lead the participants in any directions.

Uppsatsen tog utgångspunkt i det trendiga begreppet postsanning som 2016 utsågs till årets ord av Oxford Dictionaries (BBC 2016). Trenden är till följd av den postfaktiskta epok vi, av många, påstått trätt in i. En epok där relationen till sanningen kommit att bli sekundär och där ett kommunicerande gentemot känslor och övertygelse kommit att bli desto viktigare. Ingenstans är detta mer tydligt än på sociala medier. Med kritisk diskursanalys som metod undersöktes Facebookgrupperna inte rasist men och #sverigeärfullt. Frågeställningarna som söktes besvaras var vilket innehåll dominerar i de två grupperna, vilka återkommande föreställningar ges uttryck för och vad är förgivettagna fakta i dessa grupper och hur produceras och reproduceras detta? Fokus för analysen handlande om hur ramverken på de båda sidorna skiljer sig åt i sin uppbyggnad till innehåll, men fann dem också förefalla snarlika i sina diskursiva praktiker. Här fokuserades på hur båda grupperna använder sig av postsanningar och bullshit för att bygga upp ramarna inom grupperna och för att ifrågasätta andra ramar som uppstår i motstånd till den rådande dito. Gruppernas eget existensberättigande tycks finnas i konflikten till den tilltänkta motparten som ofta beskrivs som förljugen och vilseledande. / The thesis centers itself on the trendy concept of post-truth, which in 2016 was named the word of the year by Oxford Dictionaries (BBC 2016). The trend emerged due to the alleged post-factual epoch we have entered. An epoch where the relationship to truth has come to be secondary and where a communication to feelings and conviction has come to be all the more important. Nowhere is this more evident than on social media. Using critical discourse analysis as a method, the Facebook groups, inte rasist men and #sverigeärfullt were analyzed. Questions that the thesis set out to answer was what content dominates in the two groups, what recurring notions are expressed and, what are the facts in these groups and how do they produce and reproduce this? The focus of the analysis was on how the frameworks in the two Facebook groups differ in their structure, but also appear similar in their discursive practices. Here, focus was on how both groups use post-truths and bullshit to build the frameworks within the groups and to question other frameworks that arise in opposition to the prevailing one. The groups' own justification exists in the conflict to the intended counterparty, which often is described as lying and being deceitful.

In this thesis, I will examine how I worked artistically with perspectives and subjective truths in my two short films, What I Wanted to Say and TIPS. Both films are exploring the use of first-person perspective in different ways to allow the audience to experience two different opinions of the story. This exploration is the main part of my artistic research. Through my work with perspectives, I have also added the dual perspective of working as an actor-director on both films and how that method evolved through this process. This method will also be explored as a part of this thesis. In working with perspectives, I have studied when to focus on what role, both when it comes to what character’s perspective should be in focus on the screen at what time, and when to focus on what part of the actor-director role. Searching for this balance will be the focus of my artistic research, as well as looking into the possibility of allowing both roles the focus at the same time. The first film I made, What I Wanted to Say, is a love letter to a broken relationship, a short drama that explores the difficulties of ending a relationship. For this film, I used the same visuals twice but changed the voiceovers so that the visuals of the couple being in love and then fighting with each other would be influenced by each character’s subjective thoughts. The voiceovers take the audience on a reflective journey through their thoughts as Lisa leaves her lover, Oliver at the end of the film. The second film, TIPS, is a story about the newly hired bartender, Sarah, and a group of guys celebrating their friend’s birthday. Here, I worked on changing the perspectives visually through closeups and point-of-view shots, as Sarah builds up the courage to flirt for tips. This act is misinterpreted by the guys who decide to follow her home after work in pursuit of her phone number. We move back and forth between the perspective of Sarah, who learns to stand up for herself, and the self-proclaimed leader of the friend group, Pete, who learns to apologize in the end. I will be starting my thesis with an introduction to my work on the films and the artistic research. Then, I will bring up theories from my acting background to explain why I started working with perspectives and how I work with acting, before exploring the method of working as an actor-director and how I worked with that during the two film productions. The exploration of perspectives came about as a response to the seemingly growing number of echo chambers, which I will be explaining more in-depth through the research part of this thesis. Here, I will study the structure of echo chambers and look at the possibility of having narrative films counteract them. Moving over to the discussion part I will go more in-depth on how I worked with the perspectives, both when writing the script and when acting-directing. I will also look at how I worked with and developed my method of acting-directing, before concluding the thesis with a summary and how I plan to continue my work on perspectives.

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Adenosine triphosphate (ATP) is the major carrier of chemical energy in cells. The diffusion of ATP in hydrogels, which have a structural resemblance to the natural extracellular matrix, is therefore of great importance to understand many biological processes. In continuation of our recent studies of ATP diffusion in poly(ethylene glycol) diacrylate (PEG-DA) hydrogels by pulsed field gradient nuclear magnetic resonance (PFG-NMR), we present precise diffusion measurements of ATP in aqueous solutions of PEG-DA polymers, which are not cross-linked to a three-dimensional network. The dependence of the ATP diffusion on the polymer volume fraction in the hydrogels, φ, was found to be consistent with the predictions of a modified obstruction model or the free volume theory in combination with the sieving behavior of the polymer chains. The present measurements of ATP diffusion in aqueous solutions of the polymers revealed that the diffusion coefficient is determined by φ only, regardless of whether the polymers are cross-linked or not. These results seem to be inconsistent with the free volume model, according to which voids are formed by a statistical redistribution of surrounding molecules, which is expected to occur more frequently in the case of not cross-linked polymers. The present results indicate that ATP diffusion takes place only in the aqueous regions of the systems, with the volume fraction of the polymers, including a solvating water layer, being blocked for the ATP molecules. The solvating water layer increases the effective volume of the polymers by 66%. This modified obstruction model is most appropriate to correctly describe the ATP diffusion in PEG-DA hydrogels.