The aim of this thesis project is to produce an algorithm for finding a topologicalrepresentation of a polygon, called a straight skeleton, using floating pointarithmetic. Various straight skeleton algorithms are examined and discussed witha focus on time complexity and one is chosen for implementation. This implementationis then compared with the open source library CGAL with regards torunning time. The result is an algorithm which is based on an algorithm by Felkeland Obdrzalek and which, for polygons with more than five thousand vertices andthree significant digits representing points, runs around 25% faster than CGALsimplementation. Complications regarding the use of floating-point arithmetic arealso discussed..

This master thesis deals with events, dynamics and problems of mediated information seeking within the context of a new information service called "Book a librarian". The study, based on a survey and interviews both in academic and public libraries and participant observations in academic libraries, has its theoretical base in the cognitive theory of information retrieval interaction. The cognitive view is used to throw light upon the need of an ongoing dialogue during the session in order to detect the information needs of the user and to conduct a successful retrieval of information. The communicative interaction is seen as threepart interaction between the intermediary, the user and the information system, where the current cognitive states of all three participants are involved. The study shows that the cognitive obstacles for a successful mediation and information retrieval are mostly connected to participants current knowledge of the subject and of the retrieval techniques.

I mitt examensarbete har jag valt att försöka undersöka i vilken utsträckning det i en hemmastudio är möjligt att återskapa ett sound från en professionell inspelningsstudio. Denna fråga är intressant för mig då jag fastnade för hur en produktion lät i ljudbilden. Dels instrumentuppsättningen och deras rytmisering men främst soundet på helheten i mixen. Det kändes luftigt, stort och brett i lyssningsspektrat trots att det inte var så mycket instrument. Jag har alltid velat utveckla min förmåga att skapa och producera musik men har inte tillgång till så mycket kvalitativ utrustning.

The purpose of this study was to develop recommendations for using more efficient lighting and better graphic design to create a more uniform structure in the exhibition hall ?Road to the past? in Jönköping County Museum by answering the following questions at issue:1) How are the objects in the exhibition hall ?Road to the past? exposed today?2) How can you use lighting and graphic design to create structure in the exhibition and strengthen the expression in the exhibition?Our work is based on observations and open group interviews. We observed the exhibition hall ?Road to the past? during day and evening. In the same hall, we observed a guided tour that we followed up with open group interviews.

To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.

The aim of this thesis was to investigate if the robotized welding method FSW (Friction Stir Welding) could be applied for joining a rotating structure in an aero engine at Volvo Aero Corporation. FSW is expected to introduce less defects than today?s welding methods and could therefore be suitable for critical aero components. The material is the nickel based alloy Inconel 718, however a material experimentation is outside the scope of this report.The main goal of this study is to verify if the ESAB ROSIO robot based FSW-system has a suitable work space to be able to weld the rotating structure, and if the welding tool has accessibility to the joints. The FSW-process needs a rigid fixture, and a number of fix-ture concepts are presented based on a proposed weld sequence.

Introduction: Parents have been shown to be of great importance in preventing cannabis use among adolescents. Parenting practices such as control, open communication and good relations within the family have shown to be protective factors, whereas lack of communication and weak social and emotional support have been associated with an increased risk for cannabis use among adolescents. Aim: The aim of the study has been to explore parents? perceptions about their own importance in preventing cannabis use among adolescents. Method: A qualitative method consisting of focus group interviews has been used to fulfill the aim.

Syfte Syftet med arbetet a?r att so?ka fo?rsta?else fo?r utvecklingen fra?n traditionell till digitalmarknadsfo?ring samt att analysera hur fo?retag praktiskt arbetar med detta.Studien anva?nder en kvalitativ metod och data har inha?mtats fra?n ba?de prima?ra och sekunda?ra ka?llor. Empirin har samlats in genom 10 intervjuer, vilket har analyserats med hja?lp av teori och det har sedan lett till studiens slutsatser.Studien visar varfo?r det finns en o?verga?ng fra?n traditionella marknadsfo?ringsmetoder till digitala marknadsfo?ringsmetoder, hur de kompletterar varandra och vilka verktyg som fra?mst anva?nds av fo?retagen i studien.Fo?rslag till fortsattforskning är Facebook-annonsering, ma?tinstrument, SEO och Web 3.0. Dessa termer ga?r att arbeta vidare med och det a?r na?got som va?r studie har pa?visat vara viktigt.I va?r studie bidrar vi till en fo?rsta?else av va?gen fra?n de traditionella marknadsfo?ringsmetoderna till de digitala marknadsfo?ringsmetoderna.

The fertility of dairy cows is of great importance in order to maintain high production. The decline in fertility of dairy cows the latest decades can have several explanations. The large emphasis on high yielding cows and the negative genetic correlation between milk production and fertility traits could be one of the main factors for impaired fertility. To find heats and inseminate the cow at the right time is crucial to receive high conception rate. Delaval has, in corporation with FOSS, developed Herd Navigator which is a management program that measure four biological parameters in the milk; progesterone, betahydroxybutyrate, lactate dehydrogenase and urea.

The purpose of this thesis has been to develop a tool for modelling and simulating the nuclear plant Ringhals 3. The model should be used to improve the knowledge on the dynamics of the plant. Ringhals 3 is being upgraded to produce more power and a tool for analyzing the new operating conditions is needed.The work in this thesis has consisted of improving and developing an existing model of Ringhals 3 made with the modelling tool Dymola. The model has been validated by comparing the results of a simulated house load transient with data from the actual plant. Validation shows good agreement with data from the real plant.

The task of this project was to build an computer processing system for pressureregulation, in which the pressure loss over the open hydrolicvalve should be kept as low as possible. By using an cross connected proportional directional valve the valve problem could be solved. The control- and regulationproblem for the pressureregulation system was solved by using the DAQ- card NI6035E from National Instruments and the computerprogram Automatic Pressure Control 1.0 which has been software developed and written in Visual Basic. The final result showed that correct processvarible was obtained in 0,5 seconds, when the setpoint was changed in the testarea 0 - 2,5 MPa..

This essay is about the meeting of the pedagogic mission and the reality of the conditions in preschools. It is about the frustrations that I, as a pedagogue, experience when I cannot fulfill this mission. An example of this is working when understaffed.My purpose is the acknowledgment of two main areas of the curriculum: caring and learning. This essay demonstrates the diversity of the occupation and it ?s constant need of positioning.

Inom Radiostyrd Bilsport tävlas det med ett antal olika klasser som drivs av 2-taktsförbränningsmotorer. Dessa blir mycket varma och måste kylas av. Det sker med hjälp av enkylfläns som är monterad ovanpå förbränningsrummet, och som kyls av fartvinden.HP Hobbyprodukter har frågat oss om vi kan hjälpa dem att ta fram en egen kylfläns åt dem.Eftersom det ofta förekommer ovarsam behandling i tävlingssammanhang, är det ett krav attkylflänsens ska tåla detta. Den måste även avleda värme från förbränningsrummet, motorblocketoch övriga motorkomponenter effektivt. Ett önskemål är att kylflänsen ska ha ett unikt utseende,så att den är lätt att känna igen ute på banan.Arbetet har inriktat sig på prototypnivå.

Denna undersökning behandlar spel i kontext till lärande och matematik. Genom att gestalta ett spel undersökte vi, författare hur olika designval kunde påverka lärande. Målet var att spelare skulle lära sig genom situationsbaserat lärande och där genom få möjlighet att överföra sin kunskap till sitt vardagsliv. Undersökningen hade sin utgångspunkt i ANT (actor-network theory) som användes som metodologi för att analysera och reflektera över de val som gjordes. MDA (Mechanics Dynamics Aesthetics) användes som ett ramverk för att utveckla själva gestaltningen.

The purpose of this thesis has been to develop a tool for modelling and simulating the nuclear plant Ringhals 3. The model should be used to improve the knowledge on the dynamics of the plant. Ringhals 3 is being upgraded to produce more power and a tool for analyzing the new operating conditions is needed.The work in this thesis has consisted of improving and developing an existing model of Ringhals 3 made with the modelling tool Dymola. The model has been validated by comparing the results of a simulated house load transient with data from the actual plant. Validation shows good agreement with data from the real plant.