Presented in this thesis are the following theoretical investigations carried out on the non-invasive microwave hyperthermia of malignant tumours in the human body: Fundamental concepts of electromagnetic wave propagation through a biomass and its interaction with it, are discussed. Various types of applicators used for producing hyperthermia in a biomass, are also discussed. Propagation of a uniform plane electromagnetic wave through a human body is investigated for the general case of oblique incidence. Various models used for the human body have been discussed and the planar multilayer model has been chosen for this study. Reflection and transmission coefficients for both the parallel and perpendicular linear polarisations of the wave, have been determined. For normal incidence, power transfer ratio at the muscle has been defined and calculated at 433, 915 and 2450 MHz (ISM frequencies). Efects of skin thickness and also of fat thickness, on the power transfer ratio at muscle, have been studied. Effects of the thickness and dielectric constant of a bolus, and also of the dielectric constant of an initial layer, on the power transfer ratio, have been studied and their optimum values obtained at the ISM frequencies. For microwave hyperthermia, 915 MHz is recommended as the frequency of operation. Steady-state solution of the bioheat transfer equation has been obtained, assuming the biomass to be a semi-infinite homogeneous medium. Effects of various physical parameters on the temperature profile in the biomass, have been studied. Also studied is the effect of the surface temperature on the magnitude, location and the width of the temperature peak attained in the biomass. A method to determine the microwave power and the surface temperature required to produce a prescribed temperature profile in the biomass, has been developed. The transient-state solution of the bioheat transfer equation has been obtained to study the building up of the temperature profile. Procedures for the design of an open-ended rectangular metal waveguide applicator and for estimating the total microwave power requirement to produce hyperthermia in the human body, have been developed. Performance of the applicators employing linear as well as planar arrays of open-ended rectangular metal waveguide antennas, has also been studied. In order to reduce the overall physical size of the applicators, filling up of the feed waveguide with a high dielectric constant but low loss material is suggested. A simple method of obtaining the elements of the array by partitioning a large aperture by using metal walls has been adopted. Calculation of the total microwave power required by various applicators for producing hyperthermia at various depths in a biomas, have been made and a comparison of the performance of various applicators, has been presented.

Šiame darbe nagrinėjamos galimybės patobulinti plačiajuostės dielektrinės spektroskopijos metodus naudojant skaitmeninius ir analitinius daugelio modų dielektrinės skvarbos skaičiavimo metodus, tiriami (1-x)(Na1/2 Bi1/2)TiO3 - xLa(Mg1/2 Ti1/2)O3 (NBT-LMT) keramikų grupės laidumo ypatumai. Nagrinėjama galimybė pritaikyti HFSS skaitmeninio modeliavimo programą dielektrinės spektroskopijos tikslams. Naudojant šią programinę įrangą, apskaičiuojama dielektrinė ir magnetinė skvarbos komplikuotiems mikrojuostelinės linijos ir dalinai užpildyto bangolaidžio matavimo grandinių atvejams. Pateikiami patobulinti kondensatoriaus koaksialinėje linijoje ir ribotų matmenų atviro galo koaksialinės linijos matematiniai modeliai. Šie modeliai patikrinami skaitmeniniu metodu. Naudojant daugiamodį kondensatoriaus modelį, atsižvelgus į magnetinio lauko pasiskirstymą koaksialinėje matavimo grandinėje, pasiūlomas būdas pamatuoti mažai bandinio magnetinei skvarbai, kai dielektrinė skvarba didelė (dešimtim ar šimtais kartų didesnė už magnetinę skvarbą). Atviro galo koaksialinei linijai siūloma keletas kalibravimo būdų, įrenginys bandiniui prispausti prie linijos. Bešvinė NBT-LMT keramika buvo tyrinėjama dielektrinės spektroskopijos metodais. Gauti rezultatai rodo, kad NBT-LMT keramikų grupėje elektriniam laidumui galioja Maerio-Neldelio taisyklė. / Šiame darbe nagrinėjamos galimybės patobulinti plačiajuostės dielektrinės spektroskopijos metodus naudojant skaitmeninius ir analitinius daugelio modų dielektrinės skvarbos skaičiavimo metodus, tiriami (1-x)(Na1/2 Bi1/2)TiO3 - xLa(Mg1/2 Ti1/2)O3 (NBT-LMT) keramikų grupės laidumo ypatumai. Nagrinėjama galimybė pritaikyti HFSS skaitmeninio modeliavimo programą dielektrinės spektroskopijos tikslams. Naudojant šią programinę įrangą, apskaičiuojama dielektrinė ir magnetinė skvarbos komplikuotiems mikrojuostelinės linijos ir dalinai užpildyto bangolaidžio matavimo grandinių atvejams. Pateikiami patobulinti kondensatoriaus koaksialinėje linijoje ir ribotų matmenų atviro galo koaksialinės linijos matematiniai modeliai. Šie modeliai patikrinami skaitmeniniu metodu. Naudojant daugiamodį kondensatoriaus modelį, atsižvelgus į magnetinio lauko pasiskirstymą koaksialinėje matavimo grandinėje, pasiūlomas būdas pamatuoti mažai bandinio magnetinei skvarbai, kai dielektrinė skvarba didelė (dešimtim ar šimtais kartų didesnė už magnetinę skvarbą). Atviro galo koaksialinei linijai siūloma keletas kalibravimo būdų, įrenginys bandiniui prispausti prie linijos. Bešvinė NBT-LMT keramika buvo tyrinėjama dielektrinės spektroskopijos metodais. Gauti rezultatai rodo, kad NBT-LMT keramikų grupėje elektriniam laidumui galioja Maerio-Neldelio taisyklė.

Šiame darbe nagrinėjamos galimybės patobulinti plačiajuostės dielektrinės spektroskopijos metodus naudojant skaitmeninius ir analitinius daugelio modų dielektrinės skvarbos skaičiavimo metodus, tiriami (1-x)(Na1/2 Bi1/2)TiO3 - xLa(Mg1/2 Ti1/2)O3 (NBT-LMT) keramikų grupės laidumo ypatumai. Nagrinėjama galimybė pritaikyti HFSS skaitmeninio modeliavimo programą dielektrinės spektroskopijos tikslams. Naudojant šią programinę įrangą, apskaičiuojama dielektrinė ir magnetinė skvarbos komplikuotiems mikrojuostelinės linijos ir dalinai užpildyto bangolaidžio matavimo grandinių atvejams. Pateikiami patobulinti kondensatoriaus koaksialinėje linijoje ir ribotų matmenų atviro galo koaksialinės linijos matematiniai modeliai. Šie modeliai patikrinami skaitmeniniu metodu. Naudojant daugiamodį kondensatoriaus modelį, atsižvelgus į magnetinio lauko pasiskirstymą koaksialinėje matavimo grandinėje, pasiūlomas būdas pamatuoti mažai bandinio magnetinei skvarbai, kai dielektrinė skvarba didelė (dešimtim ar šimtais kartų didesnė už magnetinę skvarbą). Atviro galo koaksialinei linijai siūloma keletas kalibravimo būdų, įrenginys bandiniui prispausti prie linijos. Bešvinė NBT-LMT keramika buvo tyrinėjama dielektrinės spektroskopijos metodais. Gauti rezultatai rodo, kad NBT-LMT keramikų grupėje elektriniam laidumui galioja Maerio-Neldelio taisyklė. / One of the basic problems in measurements of the electrical properties of materials is finding relations between measured electrical values and characteristics of the material, especially when the field distribution in the device under test with a sample inside is complex. Commercial electromagnetic simulation software was used in unconventional way to calculate materials' electrical properties. Because the software is not adopted for this task, built-in optimisation option was used. In this way dielectric and magnetic properties of materials in very complex shape were calculated. The method was tested by calculation of complex dielectric permittivity of Bi1.5ZnNb1.5O7-xF2 pyrochlore ceramics as well as by calculation of both complex dielectric permittivity and complex dielectric permeability of carbon-coated capsules of Ni embedded into polyurethane matrix from experimental results. Due to the fact that using numerical methods is time consuming, a mathematical model on mode matching approach of rectangular rod in a waveguide and a new model of multimode capacitor were developed. Models were checked by numerical methods. On a high frequency, when electric field in the sample is inhomogeneous, the magnetic field in the sample is much stronger than in the transmission line. Thus, the magnetic permeability of the sample will affect scattering parameters. Based on this circumstance, the method to measure small magnetic permeability using capacitor like in coaxial line when... [to full text]

Objective: The primary aim of the study was to examine the automated linguistic analysis of the open-ended problem (PQ) and life-effects (LEQ) questionnaires to understand the psychological effects of tinnitus. Design: The study used a cross-sectional design. Participants completed online questionnaires which included demographic questions, several standardised patient-reported outcome measures (PROMs), and two open-ended questions focussing on PQ and LEQ related to tinnitus. The response to open-ended questions was analysed using the Linguistic Inquiry Word Count (LIWC) software to identify the frequency of text on various linguistic dimensions relevant to tinnitus. Study sample: 336 individuals with tinnitus. Results: The study results point to two broad findings. First, although PQ and LEQ have some similarities with PROMs (e.g. the linguistic dimension negative emotions having a weak positive correlation with anxiety and depression), no correlation with the number of dimensions suggests that the open-ended questions identify additional elements that are not captured in PROMs. Second, more linguistic dimensions from the PQ correlate with PROMs compared to LEQ suggesting that the current PROMs are problem-oriented. Conclusions: The study results support the idea that the use of open-ended questions in addition to PROMs may help optimise the efforts in examining the effects of chronic conditions such as tinnitus.

Multilingual natural language processing (NLP) is increasingly recognized for its potential in processing diverse text-type data, including those from social media, reviews, and technical reports. Multilingual language models like mBERT and XLM-RoBERTa (XLM-R) play a pivotal role in multilingual NLP. Notwithstanding their capabilities, the performance of these models largely relies on the availability of annotated training data. This thesis employs the multilingual pre-trained model XLM-R to examine its efficacy in sequence labelling to open-ended questions on democracy across multilingual surveys. Traditional annotation practices have been labour-intensive and time-consuming, with limited automation attempts. Previous studies often translated multilingual data into English, bypassing the challenges and nuances of native languages. Our study explores automatic multilingual annotation at the token level for democracy survey responses in five languages: Hungarian, Italian, Polish, Russian, and Spanish. The results reveal promising F1 scores, indicating the feasibility of using multilingual models for such tasks. However, the performance of these models is closely tied to the quality and nature of the training set. This research paves the way for future experiments and model adjustments, underscoring the importance of refining training data and optimizing model techniques for enhanced classification accuracy.

Life in today’s world is characterized by complexity and rapid change. Twenty-first century skills and especially mathematical understanding are supposed to crucially contribute to meeting the demands of our world since mathematics offers strategies to structure or simplify complex problems. An open question is which teaching practices are appropriate to provide all students with such skills and to broaden the participation of underprivileged students. The present article explores these aspects by focusing on complex tasks, a practice that can be considered highly accepted in the context of mathematics education all over the world. We will concentrate on the perspective of the German mathematics education community as the foundation of our considerations. Based on an analytical investigation of mathematical literacy and twenty-first century skills (such as creativity, critical thinking, or problem-solving), we will address central ideas and characteristics of complex mathematical tasks. To complement the analytical approach, we will illustrate their characteristics as well as possible intersections with twenty-first century skills by presenting an elementary school teaching experiment. Finally, we will critically discuss the potentials and pitfalls of complex mathematical tasks from an abstract perspective and conclude by debating practical consequences for organizing mathematical learning-teaching-processes.

Today's Swedish mathematics education is largely textbook-bound. At the same time, the textbooks are not reviewed, quality assured or checked by the curriculum in mathematics. The purpose of this study was to investigate the prevalence of open assignments and what abilities these helped the students develop. As a teacher, it is important to be aware of what tasks students encounter as well as what abilities these will train. Previous research shows that open-ended assignments are very helpful for the development of mathematical abilities for students. As an analytical starting point, Sullivan and Lilburn’s (2002) criteria for open-ended questions and MCRF's framework (Lithner et. al, 2010) for mathematical abilities were used. The analysis revealed that there was little data that fell under the criteria for open-ended questions. In the available tasks, they get to develop several mathematical abilities. “Favorit matematik” was the textbook that offered the greatest variety of tasks for developing mathematical abilities in the open-ended assignments that existed.

Modern humour appears to initiate the deconstruction of modern correspondence thinking. A close examination shows the opposite, namely that modern humour forms part of correspondence thought in a complicated reciprocal relationship of disruption and support. Ironically, humour is particularly suited to explicating the deconstruction of correspondence thinking in poststructuralist language theories by being prone to refute cornerstone principles of modernism such as truth, rationality, reliability and permanence. This dissertation focuses on the exceptional suitability of humour to adapt to the loss of the centre and to demonstrate the shift from the modernist ontological approach to the postmodernist creative metaphorical approach to art. Humour, like metaphor, reinvents meaning rather than discovers it; it remains open-ended instead of offering closure. It becomes a valid creative option and enters a new dynamic into a postmodern culture of play where truth and meaning remain infinitely suspended in an ungrounded state of possibility. / Art History, Visual Arts & Music / M.A. (Visual Arts)

The aim of the study was to investigate classroom discourse among high school natural science students in Swaziland. The research problem was: Can student interactions tell us something about the negotiation of understanding during natural science teaching? A qualitative approach was used, specifically, the observational case study style. The population comprised three Form 4 students and their natural science teacher, purposely selected. Data was collected using the non-participant observation and the standardised open-ended interview methods. The collected data was analysed using the discourse analysis approach. The analysed data indicated that prevailing discourse patterns were teacher and student talk, as well as written work. A conclusion was that student classroom discourse in the natural sciences should be encouraged among all students for improved understanding and meaning making. / Science and Technology Education / M. Ed. (Natural Science Education)

Professional competencies are explicitly identified in the primary learning outcomes for science and engineering degrees at many tertiary institutions.  Fulfillment of the requirements to equip our students with these skills, while formally acknowledged as important by all stakeholders, can be hard to demonstrate in practice.  Most degree awarding institutions would have difficulties if asked to document where in degree programs such competencies are developed. The work in this thesis addresses the issue of professional competencies from several angles.  The Open-Ended Group Project (OEGP) concept is introduced and proposed as an approach to constructing learning environments in which students’ development of professional competencies can be stimulated and assessed.  Scholarly, research-based development of the IT in Society course unit (ITiS) is described and analyzed in order to present ideas for tailoring OEGP-based course units towards meeting learning objectives related to professional competence.  Work in this thesis includes an examination of both the meanings attributed to the term professional competencies, and methods which can be used to assess the competencies once they are agreed on. The empirical work on developing ITiS is based on a framework for educational research, which has been both refined and extended as an integral part of my research.  The action research methodology is presented and concrete examples of implementations of different pedagogical interventions, based on the methodology, are given.  The framework provides support for relating a theoretical foundation to studies, or development, of learning environments.  The particular theoretical foundation for the examples in this thesis includes, apart from the action research methodology, constructivism, conceptual change, threshold concepts, communities of practice, ill-structured problem solving, the reflective practicum, and problem based learning. The key finding in this thesis is that development and assessment of professional competencies is not a pipe dream.  Assessment can be accomplished, and the OEGP concept provides a flexible base for creating an appropriate learning environment for this purpose. / <p>Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 738</p>