| 1. |
- Mehanovic, Sanela
(author)
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The Potential and Challenges of the Use of Dynamic Software in Upper Secondary Mathematics : Students’ and Teachers’ Work with Integrals in GeoGebra Based Environments
- 2011
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Licentiate thesis (other academic/artistic)abstract
- An introduction of computer software into mathematics classrooms makes the didactical situation more complex compared with previous learning environments (Blomhøj, 2005). A technological tool becoming a mathematic work tool in the hands of the students is a process that has turned up unexpectedly complex (Artigue, 2002). In addition to this problem, the teachers as the users of the tool go through the same process, while, at the same time, trying to integrate the tool into their teaching activities in a meaningful way. For these reasons it seems important to contribute to the research focused on the learning and teaching conditions in environments, where computer software is newly introduced, in order to better understand impacts of the introduction of different software in mathematics classrooms.In this study the dynamic mathematical software GeoGebra was used. GeoGebra is freely available for a number of platforms and has drawn much attention during the last years with growing user communities (www.GeoGebra.org). However, being generally available just recently, there are, comparatively, few studies on the use of GeoGebra in classroom settings.In this thesis the introduction and integration of GeoGebra was investigated in two studies with different perspectives. In the first study students’ work with GeoGebra in their mathematical activities related to the integral concept has been researched. In the second study teachers’ utilization of the didactical potential has been investigated. The results of the two studies show that GeoGebra as a mathematical tool in the hands of the students and the teachers can have a significant role in supporting their mathematical work if exploited in a, from a didactical perspective, adequate way. A learning and teaching environment based on GeoGebra bring with it a possibility to work with mathematical concepts in a broader way compared with blackboard based classrooms. GeoGebra’s facilities makes it possible to communicate mathematics in different ways and expressing mathematical concepts in different representations in a more direct way than in non dynamical environments. Communicating mathematics in different ways and expressing mathematics knowledge through different representations is of significant importance for students, not least in relation to the new curriculum for mathematics in Sweden (The Swedish National Agency for Education, 2011), where these aspects are explicitly named as aims for students to work towards.On the other hand, the investigations also showed that the introduction and the integration of GeoGebrawas a complex process for both the students and the teachers in this research. The introduction and integration of the software in the students’ mathematical activities made the didactical situation more complex and a differentiation of students’ work with the software was observed. For some students the use of the software seemingly supported their mathematical work, and at the same time for some students the result was the opposite; the use of the software was seen as a disturbing factor in their mathematical activities. When it comes to the study of teachers’ work with GeoGebra the investigations revealed that they encountered different types of obstacles that prevented them from utilizing the full didactical potential of the software in their teaching of mathematics. Three different types of obstacles were identified:technical - a teacher is not able to operate the software in the intended way;epistemological - a teacher is not aware of the didactical potential of GeoGebra and howto exploit it in in a way that supports students’ learning of integrals;didactical - a teacher is not aware of the complexity of technology based environments or he/she is aware of this aspect, but not comfortable with his/her competence in carrying out the process of integration of the software into his/her teaching without external help and support.Even if it is difficult to see the software detached from the context in this research, it seems that many of the obstacles perceived by the teachers in the experimental group, as well as difficulties students perceived in their work with the software, were related to the fact that they were inexperienced with the software and, consequently, lacked in knowledge in how to exploit its features in their mathematical activities. As it seems, the teachers would encounter the same obstacles every time they try to integrate a new, to them unfamiliar, software into their teaching practice. Also many of the students would experience same difficulties if they are not adequately supported in this process. Based on this, there are reasons to believe that problems with integration of GeoGebra into mathematics classrooms identified in this research would be similar in relation to integration of other dynamic mathematic software into mathematics classrooms, or even broader, other types of software as e.g. Computer Algebra Systems (CAS), as long as the integration considers the use of an unfamiliar software.
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| 2. |
- Hedvall, Per-Olof
(author)
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Situerad design för alla : till improvisationens lov
- 2007
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Licentiate thesis (other academic/artistic)abstract
- Visionen Design för Alla kan berikas genom att inriktningen på genomtänkta statiska lösningar kompletteras med ett design-för-alla-tänkande också för det dynamiska och situationsbundna. Själva görandet i stunden öppnar för nya möjligheter genom att handlingspotentialen och därmed även tillgängligheten bestäms i själva aktiviteten.Beskrivning och makt är nära förknippade med varandra, och en beskrivningsförskjutning ger följaktligen också en maktförskjutning. I detta fall sker förändringen åt den berörda människans håll och mot hennes möjligheter att improvisera och handla i nuet snarare än att vara tilldelad en färdig förutbestämd ”lösning”.Uppsatsen baseras främst på arbete med datorspels-tillgänglighet i Spelhålan och med interaktiva upplevelsemiljöer i iFields. Den utgår praktiskt och teoretiskt från människan som en aktiv, kreativ och meningssökande varelse. ”Människan” ses genomgående i uppsatsen som människan med sin teknik. Som aktiv, kreativ och meningssökande kan hon dra fördel av en design inriktad inte bara på lösningar för alla utan också på rik handlingspotential. Med det förändrade synsättet blir tillgänglighet inte främst en utifrån fördefinierad egenskap utan en inifrån och i stunden egenupplevd. Den mest tillgängliga tekniken är den anpassningsvänliga och följsamma som kan kröka sig efter människan och erbjuda henne improvisationsmöjligheter och flow.I den nisch av Design för Alla som denna uppsats lyfter fram är en uppdelning i människor med och utan funktionshinder knappast meningsfull. Det avgörande är vad människan kan och vill göra av det ”mellan” som finns mellan henne och omvärlden i själva situationen. Där brukar ”lika möjligheter” inte vara det samma som ”samma möjligheter”. Insatserna i Spelhålan syftade till att tillgängliggöra ett redan befintligt ”mellan”: det i vanliga kommersiella datorspel. Genom att tillföra ett stort antal styrlösningar ökade möjligheterna för nya målgrupper att delta i denna del av ungdomskulturen. Syftet med iFields är att skapa nya ”mellan” där familjer som har barn med funktionshinder kan mötas under andra betingelser än dem som råder i vardagen. I den icke-fysiska världen kan det vara lättare än i den fysiska att bygga på individuell handlingspotential, men överspridningseffekterna till den verkliga världen kan också vara betydande.Beskrivningsförskjutningen har dynamiska effekter, inte bara på tekniksidan (där en aktiv teknik får en annan och starkare ställning) utan också på människosidan. En människa som vänjer sig vid att det i stunden finns möjligheter inom räckhåll och att hon klarar sig med hjälp av dessa präglas av sina erfarenheter till att också få andra förväntningar på att klara sig nästa gång. Förväntningarna gäller både henne själv och hennes mänskliga och tekniska omvärld.
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| 3. |
- Jönsson, Per-Anders
(author)
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Modelling and laboratory investigations on freight wagon link suspensions with respect to vehicle-track dynamic interaction
- 2004
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Licentiate thesis (other academic/artistic)abstract
- The link suspension is the most prevailing suspension system for freight wagons in central and western Europe. The system design is simple and has existed for more than 100 years. However, still its characteristics are not fully understood. This thesis emphasizes freight wagon dynamics and comprises three parts: In the first part a review of freight wagon running gear is made. The different suspension systems are described and their advantages and disadvantages are discussed. The review covers the running gear standardized by UIC and the conventional so-called three-piece bogie. Additionally five improved three-piece bogies and twelve novel running gear designs are presented. The second part focuses on the lateral force-displacement characteristics in the link suspension. Results from stationary measurements on freight wagons and laboratory tests of the link suspension characteristics are presented. To improve understanding of the various mechanisms and phenomena in link suspension systems a simulation model is developed. Link suspension systems have strongly nonlinear characteristics including a hysteresis loop. The loop exhibits usually three characteristic sections with different tangential stiffnesses. The actual contact geometry of the links and end bearings has a significant influence on the characteristics. By wear in ordinary service - as well as by geometric tolerances on new components - the contact geometry may deviate considerably from nominal geometry. Further, it seems that elastic deformation in the contact surfaces has considerable effects on the suspension characteristics, in particular on the initial rolling stiffness for small displacements. Also, flexibilities in links and end bearings influence the characteristics. It is also observed that new components after a short period of dynamic testing can exhibit a very low amount of energy dissipation, a phenomenon that is also indicated in some stationary measurements on wagons. To summarize the second part, it appears that the link suspension characteristics are very sensitive to several factors being hard to control in the real world of freight wagon operations. The various stiffnesses and hysteresis loops have a considerable variation and may have a strong influence on the ride qualities of vehicles. As long as the characteristics can not be controlled within closer limits than found in this study, there is a strong need for sensitivity analysis to be made, both in predictive multibody simulations of vehicle dynamics, as well as in verification and acceptance tests. In the third part a study on the possibility to improve ride qualities of freight wagons with link suspensions is presented. Parametric studies with multibody dynamic simulations on freight wagons equipped with link-suspension bogies are performed. The effect of supplementary friction and hydraulic damping is investigated under various running conditions: speed, loading, tangent and curved track, wheel-rail contact geometry, track gauge and track irregularities. Substantial improvements of the lateral running behaviour of wagons with link suspension bogies can be achieved - both at ordinary speeds and at increased speeds - by using a proper combination of supplementary hydraulic dampers. Speeds up to 160 km/h could be realistic.
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| 4. |
- Jönsson, Per
(author)
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Impact Analysis : Organisational Views and Support Techniques
- 2005
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Licentiate thesis (other academic/artistic)abstract
- Change is unavoidable in software development. During the entire lifecycle of a product, from concept to retirement, the environment changes; the needs of customers or the market change and grow, and with them the requirements on the system being developed. Under these conditions, it is crucial to have strong change control in order to be able to manage change in an orderly fashion. Unmanaged change may lead to fault-prone software, thereby increasing test, support and maintenance costs. Impact analysis is the activity of analysing a change and assessing the consequences it may have, including necessary modifications to development artefacts. Thus, it serves as a very important change control tool. Furthermore, as the consequences may include aspects of time, resources, market and technology, impact analysis has the potential to be a valuable product and project management tool. To this date, impact analysis research has mainly been conducted in the software maintenance field. However, as impact analysis clearly has a wide field of application, it is relevant to study it in other contexts as well. This thesis looks at impact analysis from a requirements engineering perspective, with particular focus on organisational aspects related to different roles and organisational levels. The results show that impact analysis indeed has a diverse nature with respect to these aspects. Furthermore, the thesis includes the proposal and evaluation of a semi-automatic method for performing impact analysis. Finally, it provides a thorough evaluation of a technique for reconstructing missing data in surveys.
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| 5. |
- Lundblad, Thomas
(author)
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Simulerad verklighet i gymnasieskolans fysik : En designstudie om en augmented reality simulering med socio-naturvetenskapligt innehåll
- 2012
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Licentiate thesis (other academic/artistic)abstract
- This thesis takes its standpoint in the declining interest for science studies in Sweden and abroad. According to Dillon and Oshorne (2009), science education is not conceived as an education for the lllajority of students. It is targeted at supplying the society with future scientists, ignoring the need for a science education for all students. One way to include more students in science activities can be to let them investigate the world outside school and make connections between these investigations and their own personal life (Aikenhead, 2007). Socio-scientific issues (SSJ) arc brought forward by many ,,'Searchers as a pedagogical model to engage students in developing scientific knowledge while dealing with prohlelTIs situated in their society.The thesis describe the design and use of an Augmented Reality (AR) simulation (Klopfer, 200S) called Transformer where students engage in a role play concerning a socio-scientific dilemma situated in their local environment. Students use smartphones equipped with the AR-simulation to collect information and take measurements in their local environment. The different roles use their collected information in a concluding debate where they argue for their standpoint in the dilemma.The design and use of Transformer was investigated in two studies. The first study describes the design of Transformer and investigates in how the silTIulation influenced the students. In the second study students actions in a debate was investigated concerning which sources if information students use, how the socio-scientific nature of the issue was expressed, and how the roles influenced the use of information. Results from the studies give evidence of engaged students that experienced the dilemma as actual and relevant.Their argumentation in the debate was focused around the dilemma and meets the criteria for socioscicntific reasoning stated by Sadlcr, ]larab and Scott (2007). The results also points at parts of the design vvhere there is room for improvements. These experiences will infonn the next step in a design based research cycle.The thesis shows that a combination of AR and SS! is a feasible way for practitioners to situate pedagogicaUy relevant content in an enVlrOlllnent outside school.
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| 6. |
- Nordquist, Annie
(author)
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A physical modeling study of top blowing with focus on the penetration region
- 2005
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Licentiate thesis (other academic/artistic)abstract
- This thesis work aimed at increasing the knowledge regarding phenomena occurring when gas is injected using a top-blown lance on to a bath. All results are based on physical modeling studies carried out both using low and high gas flow rates and nozzle diameters ranging from 0.8 mm to 3.0 mm. At the low gas flow rates, the penetration depth in the bath was studied. The experiments focused on studying the effect of nozzle diameter, lance height and gas flow rate on the penetration depth. It was found that the penetration depth increases with decreasing nozzle diameter, decreasing lance height and with increasing gas flow rate. The results were also compared with previous work. More specifically, it was studied how the previous published empirical relationships fitted the current experimental data. It was found that the relationships of Banks [1], Davenport [2], Chatterjee [3] and Qian [4] agreed well with the experimental data of this investigation for nozzle diameters of 2.0 mm and 3.0 mm. However, for smaller nozzle diameters there were considerable deviations. Therefore, a new correlation heuristically derived from energy conservation consideration was suggested and showed better agreement for small nozzle diameters. The experiments carried out at higher gas flow rates focused on the study of swirl motion. The effects of nozzle diameter, lance height, gas flow rate and aspect ratio on the swirl motion were investigated. The amplitude and period of the swirl as well as the starting time and the damping time of the swirl were determined. The amplitude was found to increase with an increased nozzle diameter and gas flow rate, while the period had a constant value of about 0.5 s for all nozzle diameters, gas flow rates and lance heights. The starting time for the swirl motion was found to decrease with an increased gas flow, while the damping time was found to be independent of gas flow rate, nozzle diameter, lance height and ratio of depth to diameter.
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| 7. |
- Norlin, Per, 1956-
(author)
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Bilderboksstunden i förskolan : Småflodhästarna och Kenta möter Piraten och Spenaten
- 2013
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Licentiate thesis (other academic/artistic)abstract
- Uppsatsen Bilderboksstunden i förskolan undersöker potentialer i två välkända svenska bilderböcker under tretton videofilmade bilderboksstunder på två förskoleavdelningar i skilda kommuner. Undersökningen är gjord utifrån de föreställningsvärldar (Langer 1995:5) och den textrörlighet (Liberg m.fl. 2010c:46) som barn och pedagoger använder. Några möjliga innehållsliga teman i bilderböckerna kontrasteras mot det upptag som deltagarna ger uttryck för i dialogen – som förs med såväl språkliga som kroppsliga uttrycksmedel under tiden som boken blir läst – och i korta samtal direkt efteråt.Föreställningsvärldar skapas utifrån flera olika hållningar. Vanligt är att, till skillnad från vad forskning i skolans värld dokumenterat, röra sig ut mot egna erfarenheter. Barnen som är mellan tre och sex år engagerar sig starkt i det innehållsliga temat det farliga i den ena bilderboken. Pedagogerna följer barnen i deras intressen, men när de försöker väcka tankar om underliggande betydelser svarar barnen vänligt med att styra samtalen mot upplevelser istället. I den andra boken vill pedagogerna fokusera det normkritiska temat som förskolans läroplan påbjuder. Barnens svar är vanligen undvikande utom i en bilderboksstund där en grupp pojkar starkt argumenterar, gentemot pedagogen, för könssegregerade lekar.Deltagarna ställer många gånger olika hållningar bredvid varandra genom att hastigt röra sig genom olika föreställningsvärldar. Olika föreställningsvärldar kan till och med smälta samman därför att de med hjälp av hopfantiserade lekvärldar använder element från boken, egna och gemensamma erfarenheter eller kunskaper och sina personligheter. Vid upprepad läsning skapade barnen lekfulla kontrafaktiska resonemang utifrån böckernas handling.Förutsättningen för att bilderböckernas rika tolkningsmöjligheter ska kunna utnyttjas är att yttrandefriheten respekteras och att barnen får avbryta läsningen. Den mest intensiva dialogen uppstår ofta i samtalet under själva läsningen, medan samtalet efter läsningen ofta avstannar. Det verkar också som om barnens förmåga att återknyta till upplevelsen av boken är omedelbar när läsningen återupptas.Uppsatsen visar att det är möjligt att utveckla rika föreställningsvärldar och stor textrörlighet vid läsning av bilderböcker i förskolan. Detta sker om pedagoger samtalar med barn med öppenhet för de tolkningar och fantasifulla associationer som uppkommer under läsningen, bland annat sammansmälta föreställningsvärldar. Studiens fynd pekar framåt mot hur de didaktiska potentialerna i bilderboksstunden skulle kunna samverka med förskolans övriga verksamhet i ett mer utvecklat litteraturarbete.
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