Neste trabalho, estudamos os grupos de tranças em superfícies visando encontrar apresentações para estes grupos em superfícies fechadas orientáveis de gênero g >= 1 ou superfícies fechadas não orientáveis de gênero g >= 2. Uma consequência destas apresentações é resolvermos o problema da palavra, que consiste em encontrar um algoritmo para decidir quando uma dada palavra num grupo definido por seus geradores e suas relações é a palavra trivial / In this work, we find presentations for surface braid groups either in closed orientable surfaces of genus g >= 1 or in closed non-orientable surfaces of genus g >= 2. A consequence of this presentations is to solve the word problem, which consists in finding an algorithm to decide when a given word in a group defined by its generators and its relations is the trivial word

This thesis reports on a literature survey and an investigation that was done on the Histology course for MBChB II learners at Medunsa. All aspects of the course were investigated including the present course as well as the possibility of replacing the lectures by multimedia computer presentations and a video. The multimedia computer presentations were specially developed for the study while an earlier developed video was also included into the study. Two instruments were used to gather information from the learners. Responses from a questionnaire as well as learner records were statistically evaluated. This information as well as information gathered from the literature was used to design a new proposed course in histology. A number of issues emerged from the study. The first issue is that histology is the least favourite of all the subsections of Anatomy. Learners prefer to study their histology by watching a video. The learners who watched the video more than four times did not do better than the others. Multimedia changed the attitude of the learners towards histology to some extent. Learners have a perception, which could not be proved, that if they study with the aid of multimedia their marks and their recollection will improve. Learners often left lectures before the end or did not attend. The reason that the learners indicated for this tendency was lack of concentration. Most learners want the system of lectures changed. They want some lectures to be replaced by multimedia. Most learners rate the histology lectures as good. The majority of learners do not want the histology course to be changed into a multimedia course. From the study it is clear that the microscope can be successfully replaced by an instructivist way of learning like a video or a multimedia computer presentation. It is however not ideal to replace a constructivist way of learning, like using a microscope, with a way of learning that is only instructivist, therefore it is suggested that the microscope is replaced by another constructivist way of learning. Providing groups of learners with unique images from the histology slides to be studied and annotated was suggested. It also became clear that if a computer-based histology course is to be implemented in future, learners will have to go through a transitional phase where the lectures and practicals are gradually replaced by multimedia. / Thesis (PhD (Information Science))--University of Pretoria, 2006. / Information Science / unrestricted

In this study, I investigate how foreign language anxiety affects students’ performance during oral presentations. The study also explores how secondary school teachers in Sweden work with anxious students before, during and after an oral presentation and what approaches and exercises they find effective to use when doing so. Foreign language anxiety is a relatively new subject within language education and impacts language learning in various, mostly negative, ways. The data is collected from interviews with secondary school teachers in Sweden. The result show how these teachers identify FLA and what effects they believe it has on their students. The result also gives insight into how the teachers approach all three stages of an oral presentation to reduce symptoms that lead to increased anxiety. The study concludes by comparing the teachers’ choices to theories within language teaching to establish a pattern of what strategies are effective when dealing with FLA. In this study, I highlight the benefits of using oral presentations based on research and why every student should be given help to overcome their anxiety, so that they are prepared to use their English in high-pressure situations, such as during an oral presentation.

Though many researchers have suggested that 3D virtual environments (VEs) could provide advantages for conceptual learning, few studies have attempted to evaluate the validity of this claim. While many educational VEs share the challenge of providing learners with information within 3D spaces, few researchers have investigated what approaches are used to help learn new information from 3D spatial representations. It is not understood how well learners can take advantage of 3D layouts to help understand information. Additionally, although complex arrangements of information within 3D space can potentially allow for large amounts of information to be presented within a VE, accessing this information can become more difficult due to the increased navigational challenges. Complicating these issues are details regarding display types and interaction devices used for educational applications. Compared to desktop displays, more immersive VE systems often provide display features (e.g., stereoscopy, increased field of view) that support improved perception and understanding of spatial information. Additionally, immersive VE often allow more familiar, natural interaction methods (e.g., physical walking or rotation of the head and body) to control viewing within the virtual space. It is unknown how these features interact with the types of spatial information presentations to affect learning. The research presented in this dissertation investigates these issues in order to further the knowledge of how to design VEs to support learning. The research includes six studies (five empirical experiments and one case study) designed to investigate how spatial information presentations affect learning effectiveness and learner strategies. This investigation includes consideration for the complexity of spatial information layouts, the features of display systems that could affect the effectiveness of spatial strategies, and the degree of navigational control for accessing information. Based on the results of these studies, we created a set of design guidelines for developing VEs for learning-related activities. By considering factors of virtual information presentation, as well as those based on the display-systems, our guidelines support design decisions for both the software and hardware required for creating effective educational Ves. / Ph. D.

This thesis project describes a system to make presentations more collaborative, consisting on a mobile application using mesh technology.The mesh network may be set up through the choreography of interaction created by attendees tapping their phones together at the start of the meeting. The fluid workflow for requesting and handing over control of the projector encourages sharing and makes the interaction between presenter and audience more collaborative.The design was evaluated through a collaborative session that pointed at several future lines of work. Furthermore, we found opportunities to leverage the use of mesh networks in the workplace.Finally, we carried out two explorations of the use of projectors and movement capture for the creation of visual content. This, along with the previous work, served as a base for the argument that there is an opportunity to discover rich interaction possibilities in the combination of small, modular IoT devices to create augmented spaces.

Rädsla för att tala inför folk är ett allmänt känt fenomen som har drabbat oss alla någon gång. Muntliga presentationer är en del av svenska elevers skolgång, och det kan bidra till oro och stress hos vissa elever. Trots detta är det ett krav från Skolverket att muntliga presentationer ska genomföras av alla elever. Den första frågan och syftet med denna studie var att undersöka hur mellanstadieelever upplever att göra muntliga redovisningar. Studiens andra fråga och syfte var att studera vilka metoder pedagoger använder för att stödja och förbereda eleverna inför de muntliga presentationerna. Slutligen ställdes frågan hur undervisningen inför muntliga redovisningar visar sig i elevernas upplevelser av presentationerna. För att besvara studiens frågor svarade 84 elever på ett frågeformulär och fyra lärare deltog i semistrukturerade intervjuer om forskningsområdet. Materialet analyserades med stöd av det sociokulturella perspektivet och teorier om stress och coping. Studiens resultat visar att känslorna för presentationerna varierar, även om en majoritet av eleverna uttrycker att de känner någon form av ängslan och stress före och under sin presentation. En del elever behåller känslan av stress efteråt. Intervjuerna visade att lärarna är medvetna om elevernas oro och att de arbetar på olika sätt för att förbereda och stödja dem inför sina muntliga presentationer. Studien visar ett starkt samband mellan mindre ängslan inför muntliga presentationer och en respektfull klassrumsmiljö. Studien visar också att eleverna är öppna för, och har ett behov av, att lära sig mer om retoriska verktyg och att tala inför en grupp. En fortsatt studie med fokus på hur elever upplever sina muntliga presentationer, kan vara av vikt för skolans praktik. Detta för att få en större förståelse för elevernas känslor kring muntliga presentationer, och för utvecklingen av metoder pedagogerna bör använda för att förbereda och stödja eleverna. / Anxiety of speaking in front of people is a commonly known phenomenon that has hit all of us at one time or another. Oral presentations are part of Swedish students' schooling, and it can contribute to anxiety and stress in some students. Despite this, it is a requirement from the Swedish National Agency for Education that oral presentations be conducted by all students. The first question and aim of this study was to investigate how elementary school students experience performing oral presentations. The second question and aim of the study was to study what methods educators use to support and prepare students for the oral presentations. Lastly, the question was asked how lessons in preparation for oral presentations is reflected in students' experiences of them. In order to answer the study's questions, 84 students answered a questionnaire, and four teachers took part in semi-structured interviews about the research area. The material was analysed using the sociocultural perspective and theories of stress and coping. The results of the study show that feelings about the presentations vary, though a majority of the students express feeling some level of distress before and during their presentation. Some students keep the feeling of stress afterwards. The interviews revealed that teachers are aware of students' concerns and that they work in different ways to prepare and support them for their oral presentations. The study shows a strong correlation between less apprehension about oral presentations and a respectful classroom environment. The study also shows that students are open to, and have a need for, learning more about rhetorics and speaking in front of a group. A further study focusing on how students experience their oral presentations, may be of value for school practice. This to gain a greater understanding of students' feelings about oral presentations, and for the development of methods educators should use to prepare and support students.

The purpose of this study is two-fold: 1. to determine whether or not certain poster presentations affect the food acceptance of elementary school children, and 2. to determine which method of presenting a poster had the most affect upon the child's food acceptance.

Music as a hub in school presentationsThe aim of the study is to elucidate how making meaning is constituted when lower secondary pupils play music when giving accounts of other school subjects than music. The empirical material consists of four presenta- tions in the subjects of physics, religion and Swedish, which were filmed during ordinary lessons in a lower secondary school. In addition the data consists of nine filmed stimulated recall interviews with the pupils and their teachers, which were also filmed.Social semiotic multimodality constitutes the study’s theoretical and methodological point of departure. The perspective enables investigation of the pupils’ playing of music and music in its multimodal context, and of how different dimensions of meaning are constructed. The filmed presentations were transcribed into music scores in order to visualise the multimodal events of the presentations. Three different categories of meaning were used, ideational, interpersonal and textual meaning, to analyse how music relates to other modes of communication.The results show how the temporal functions of music serve as frame- work and motor, what the music narrates in relation to the subject content and what interpersonal relations the music communicates. The young peo- ple’s knowledge of music manifests itself in the different accounts as an ability to use and adapt musical knowledge to a context where another sub- ject than music is in focus. The presentations of Swedish are travesties of well-known songs and the pupils stick to the given form. In the other presen- tations the pupils themselves had compiled the music and the result was a form of musical works where the music does not follow any model or certain genre. The informants think that this working method implies that the work is experienced as meaningful both to themselves and to the audience.

How fashion is being presented today? A retrospective research into the history of the fashion shows in order to observe and examine the metamorphosis of the runway presentations of the present time. Fashion designers from the Swedish School of Textiles have participated in the thesis' interview as to express their point of view and elaborate on the issue.

The goal of our studies was to test the effect of segmentation, cueing, and 2D/3D presentations to foster complex animation rocessing. The material was an upright mechanical piano system. We used an eye tracking system which provides information about learners' attention direction during the animation processing. We analyzed the effect of the format presentations and the eye movements during learning. Based on animation and multimedia research background, four experiments were conducted. In the first experiment the effect of the presentation of simplified external representations on learning from complex animation was investigated. Experiment two and three aimed at studying the cognitive processes involved in learning to complex mechanism system with new cueing techniques with spatial-temporal colored tokens. In the fourth experiment, 2D and 3D presentation of the same animated content were compared. Results of these experiments showed that (1) the use of a dual format presentation is better for developing a dynamic mental model from the animation than a single format, (2) the signaling strategies using cued tokens of dual format can guide efficiently learner's building of mental model and can enhance learner's comprehension of complex system, (3) a sequential format presentation followed by an animation format presentation helps the learner to understand the key stages of a dynamic process and to create a high quality mental model, (4) 3D animation presentation is better than 2D animation presentation to direct attention on relevant component of the animation. For depth processing, comprehension with 3D animation presentation is better than 2D animation format. Eye tracking measures provided insights into how people understood and learned complex systems. The analysis of eye tracking also contributed to the understanding of the subject's perceptual processing during learning. Overall, results provide a significant contribution in the field of learning with complex animation. Recommendations in the ergonomics area for the design of animations are proposed.