This study of cooperative learning in post-secondary engineering education investigated achievement of engineering students enrolled in two intact sections of a computer-aided drafting (CAD) course. Quasi-experimental and qualitative methods were employed in comparing student achievement resulting from out-of-class cooperative and individualistic learning structures. The research design was a counterbalanced, repeated measures, nonequivalent control group design. During the first half of the semester, one course section served as the experimental group (cooperative learning) and the other section served as the control group (individualistic learning). During the second half of the semester, the treatment and control conditions were switched to the other section. Data collection involved a pretest, a mid-term exam, a final exam, weekly homework drawing grades, an introductory demographic survey, weekly peer reviews, and interviews. The data analyses showed that the differences between the treatment and control group means on the mid-term and final exams were not significant. However, the treatment group means on the weekly homework drawings were significantly higher than those for the control group in each half of the semester. The data revealed main effects of race, prior experience, time of achievement test administration, and prerequisite grade. A post-hoc analysis did not show significant differences among the various levels of prerequisite grade. Also, there were first-order interactions for gender-by-time, experience-by-time, method-by-time for the year as engineering major demographic variable, and method-by-academic year. Qualitative data revealed that most participants had positive group experiences, more participants preferred working in cooperative groups during more difficult activities than introductory material, academically stronger participants might have "carried" weaker participants in the cooperative groups, and there were times identified for cooperative group work during which groups did not work cooperatively. Based upon the findings in this study, one might reasonably conclude that cooperative and individualistic learning structures result in approximately equal student achievement. Thus, when deciding on the use of one learning structure over the other, instructors might focus on which approach seems more appropriate/practical for a particular instructional activity. / Ph. D.

Detta projektarbete genomfördes i samarbete med Elpress AB med syftet att effektivisera framtagandet av kundunika produkter. Elpress AB tillverkar kontaktpressningssystem för fixering av kablar vid kontaktytor, där produktionen av kabelskor utgör en betydande del av verksamheten. Företaget säljer både standardprodukter och kundunika produkter som specialanpassas efter kundens önskemål. För att underlätta framtagandet av kundunika produkter skapades i detta projektarbete en konfigurerbar modell av en kabelsko av typen KRF i CAD-visualiseringsprogrammet Dynamaker. Förutom framtagandet av appen har projektet även innefattat analys av data från tidigare tillverkade kundanpassade kabelskor för att få information om begränsningar kring vad som är möjligt att tillverka. Under appens utvecklingsprocess skapades två prototyper och en slutversion. I slutversionen visas kabelskon från två olika vyer och dess mått och egenskaper kan justeras inom de framtagna begränsningarna. Det finns även möjlighet att ladda ned en ritning på kabelskon efter färdig konfiguration. Slutresultatet uppfyllde projektets syfte och appen kunde dessutom utvidgas till fler storlekar av kabelskon KRF.

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Intresset för vattenskotrar har ökat dramatiskt i Sverige de senaste åren och nya problem har upptäckts i och med detta. I takt med att klimatet förändras blir växtlighet på skroven till vattenskotrar ett allt större problem. En vattenskoter som ligger i vattnet en hel sommar blir en optimal yta för havstulpaner och andra organismer att växa och leva på. Detta resulterar i högre bränsleförbrukning som i sin tur bidrar till ökade utsläpp av växthusgaser, vilket bidrar till klimatförändringarna. Syftet med detta arbete är att hitta en lösning som innebär att en vattenskoterägare kan lyfta upp sin vattenskoter ur vattnet varje gång den parkeras, samt att skapa en lönsam produkt åt Metallindustri i Luleå där arbetet utfördes. I början av projektet samlades inspiration från existerande modeller av vattenskoterlyftar innan två koncept framställdes. Arbetet bestod därefter av att vidareutveckla ett av dessa koncept med hjälp av digitala ritverktyg, Computer-Aided Design (CAD), och hållfasthetsberäkningar. På grund av begränsad tid avgränsades arbetet till att konstruera en lyft som endast lämpar sig på fasta bryggor. Baserat på uträkningar och navigering i CAD resulterade arbetet i en konstruktion av en vattenskoterlyft med manuell vinsch och avtagbara bärarmar som uppfyller de flesta kraven som ställdes. Arbetet resulterade även i ritningsunderlag tillräckligt sofistikerade att skickas till verkstad för påbörjad produktion. / The interest in Jet Skis has increased drastically in Sweden in recent years, and new problems have been discovered as a result. As the climate changes, vegetation on the hulls of jet skis becomes a major problem. A Jet Ski that is kept in the water for an entire summer constitutes an optimal surface for barnacles and other organisms to grow and live on. This results in higher fuel consumption, which contributes to increased emissions and, thus, to climate change. The purpose of this work was to find a solution so that a Jet Ski owner can lift the Jet Ski out of the water every time it is parked, and to create a profitable product for Metallindustri in Luleå, where the work was performed. At the beginning of the project, inspiration was gathered from existing models of jet ski lifts before two concepts were developed. The work then consisted of further developing one of these concepts using digital drawing tools, i.e. Computer-Aided design (CAD), and strength calculations. Due to limited time, the work was restricted to constructing a lift that is only suitable for fixed bridges. Based on calculations and overview in CAD, the work resulted in a design of a jet ski lift with removeable lifting arms and a manual winch that meets most requirements. The work also resulted in drawings sufficiently sophisticated to be sent to a workshop for commenced production.

På BillerudKorsnäs pappersbruk i Karlsborg finns det arbetsmoment vid en bestrykningsmaskin som riskerar att utsätta operatörerna för förslitningsskador. Bestrykningsmaskinen är en maskin där pappret bestryks med en smet för öka glansen och få en jämnare yta. Arbetsmomentet innebär att sprätta bort de yttersta varven papper från de färdiga rullarna med bestruket papper, eftersom det inte uppfyller kvalitetskraven med avseende på glans och ytjämnhet. Vissa papperskvaliteter är väldigt töjbara vilket innebär en stor belastning på axlar och händer när man sprättar pappret. Syftet med examensarbetet var att tillsammans med operatörer och processingenjörer, designa och konstruera en ny modell på sprättare, som har förbättrad funktion och ergonomi för att minimera risken med förslitningsskador. Avgränsningar gjordes till att konstruera en sprättare för sprättning av färdigt bestruken kundrulle vid rullmaskinen.Olika konceptförslag togs fram med hjälp av Computer-Aided-Design (CAD) och prototyper tillverkades därefter med hjälp av 3D-skrivare för testning och utvärdering. Riskbedömning utfördes för att sammanställa vilka risker den nya sprättaren medförde. Arbetet resulterade i en färdigtillverkad fungerande prototyp med tillhörande ritningsunderlag tillräckligt detaljerat för en framtida serietillverkning.Slutsatsen är ett nytt skärverktyg som nu har designats och tillverkats anpassat efter operatörernas krav på ergonomi och funktion, och därmed minskar riskerna med att utsätta operatörerna för förslitningsskador. / At BillerudKorsnäs' paper mill in Karlsborg, there is working tasks on a coating machine that risks exposing the operators to wear and tear injuries. The coating machine is a machine where the paper is coated with a glaze to increase the gloss and get a smoother surface. For this machine, one of the working tasks is, by using a hand tool, cut the outer layers of paper from the finished rolls of coated paper, which is necessary to avoid quality loss regarding to gloss and surface smoothness. Some of the paper qualities is very tough and stretchable, which means a great strain on the shoulders and hands when cutting the paper. The purpose of the project was to, together with operators and process engineers, design and construct a new model of the cutting tool with improved function and ergonomics to minimize the risk for wear and tear injuries. The work is limited to the construction of a cutting tool for a completely coated paper roll at the rolling machine.Different concepts proposals were developed by using Computer-Aided-Design (CAD) and prototypes were then manufactured for testing and evaluation by using 3D printers. A risk assessment was performed to compile which risks the new cutting tool entailed. The work resulted in a manufactured well-working prototype with drawings and 3D-models suitable to initiate mass production of the tool.The conclusion is a new cutting that has been designed and built to suit the operators’ requirements of ergonomics and function, which reduces the risks of exposing the operators to wear and tear damage.

Rototilt Group AB arbetar med att konstruera och utveckla tiltrotatorer, maskinfästen, styrsystem och redskap till grävmaskiner. En central komponent för tiltrotatorn är redskapsfästet som kopplar samman tiltrotatorn med ett redskap, till exempel en grävskopa eller en grip. I dagsläget är modellen HS03 baserad på en svetsad konstruktion, men då seriestorleken av denna konstruktion har ökat är det fördelaktigt att övergå till en gjuten konstruktion. Målet med examensarbetet är att skapa underlag för ett nytt gjutet redskapsfäste till modellen HS03. Projektet avgränsas till att omfatta 3D underlag med tillhörande dimensionering för det gjutna redskapsfästet, det här examensarbetet omfattar ej tillverkning av den färdiga detaljen. Examensarbetet resulterade i två stycken CAD-modeller som beskriver redskapsfästet. Den första CAD-modellen beskriver gjutgodsets geometri. Den andra CAD-modellen beskriver den färdiga detaljen, det vill säga redskapfästets färdiga geometri. Då prioriteringen legat på att optimera redskapfästets geometri har inga ritningar upprättats då det inte har funnits tid till detta. Tanken är att Rototilts konstruktörer kommer fortsätta arbetet med att färdigställa ritningarna, för att slutligen välja en leverantör av gjutgods som kommer tillverka redskapsfästet. Slutsatsen av arbetet är att det är möjligt att designa ett gjutet redskapsfäste genom simuleringsdriven konstruktion. Genom att välja gjutning som tillverkningsmetod kan tillverkningskostnaden, materialet och vikten minimeras vilket maximerar resurseffektiviteten. / Rototilt Group AB works to design and develop tiltrotators, machine mounts, control systems, and tools for excavators. A central component of the tiltrotator is the tool attachment that connects the tiltrotator with a tool, such as a backhoe or grapple. Currently, the HS03 model is based on a welded construction, but as the batch size of this design has increased, it would be beneficial to switch to a casted construction. The goal of the project is to create a basis for a new cast tool holder for the model HS03. The project is limited to create 3D models and determine the dimensions of the casted tool mount only. It does not include actual manufacturing of the final part. The thesis resulted in two CAD models that describes the tool attachment. The first CAD model describes the geometry of the casting. The second CAD model describes the machining, i.e. the finished geometry of the attachment. As the priority was to optimize the geometry of the implement attachment, drawings have not been created due to time limitations. The idea is that Rototilt's engineers will continue finalizing the drawings to finally choose a casting supplier who will manufacture the tool mount. The conclusion of the work is that it is possible to design a cast tool attachment through simulation-driven design. By choosing casting as a manufacturing method, manufacturing cost, material, and weight can be minimized, which maximizes resource efficiency.

<p>U disertaciji se prikazuje modularni sistem za projektovanje alata za<br />injekciono presovanje plastike. Analizirani su različiti prilazi u<br />projektovanu alata. Prikazana je koncepcija i funkcionisanje<br />razvijenog sistema. Verifikacija sistema je izvr&scaron;ena na konkretnim<br />plastičnim proizvodima. Na kraju su dati odgovarajući zaključci i<br />mogući pravci budućih istraživanja.</p> / <p>The dissertation shows the development of the modular system for<br />mold design for plastic injection molding. Different approaches were<br />analyzed in the field of mold design. The concept and functioning of<br />the developed modular system is presented. Validation of the<br />proposed system is made with the specific plastic parts. At the end<br />the appropriate conclusions and possible directions for future<br />research are given.</p>

Este trabalho trata, inicialmente, de uma extensa investigação acerca do efeito que o processo de digitalização da imagem exerce num esquema de processamento de imagens em mamografia. Como todas as etapas de processamento tomam por base a imagem original digitalizada, os diferentes equipamentos, tecnologias, softwares de aquisição e características do processo contribuem para produzir diferentes aspectos na digitalização de um mesmo filme mamográfico. Por conseguinte, as etapas envolvidas do pré-processamento à classificação, passando principalmente pela segmentação dessas imagens, poderão produzir diferentes resultados dependendo da fidelidade da imagem digital em relação à mamografia original. Assim, essa pesquisa focaliza uma avaliação comparativa das características das imagens mamográficas adquiridas em diferentes sistemas de digitalização, tomando por base o efeito que esse processo exerce na sensibilidade de módulos de um esquema CAD (de Computer-Aided Diagnosis) previamente desenvolvido em nosso grupo. Com base nisso, propõe-se um modelo computacional que permite compensar as eventuais degradações introduzidas no processo de digitalização, em busca de uma maior uniformidade das imagens mamográficas digitais, independentemente do equipamento utilizado na digitalização. Testes conduzidos com as imagens digitais geradas em vários sistemas diferentes - desde equipamentos mais comuns, com adaptadores de transparência, até os mais sofisticados, com varredura a laser, e de alto custo - utilizando o driver de digitalização aqui proposto mostraram que houve um aumento da sensibilidade na detecção de microcalcificações para todos os casos em relação à utilização das imagens originalmente digitalizadas sem a aplicação do modelo. Além disso, foi significativa também a redução na taxa de falsos-positivos (entre 70 e 90%) nas mesmas condições. Como efeito, a presente proposta torna acessível a qualquer instituição radiológica a possibilidade de aplicação de esquemas de processamento para auxiliar a detecção e/ou diagnóstico de estruturas suspeitas em mamografia, mesmo que utilizando digitalizadores menos sofisticados - e, portanto, de menor custo - para a produção das imagens mamográficas digitais e sem perda de qualidade do desempenho. / This work corresponds to an extensive investigation on the effect of the image digitization process on an image processing scheme in mammography. As all the processing steps are based on a digitized image, different equipment, technologies, acquisition softwares and characteristics regarding such a procedure contribute to yield different features during the digitization of a same mammographic film. As a consequence, all the steps since the pre-processing up to the classification, mainly the images segmentation, could give different results depending on the digital image fidelity relatively to the original mammogram. Therefore, this research concentrates on a comparative evaluation of mammographic images acquired from several digitization systems, concerning the effect of this procedure on the sensitivity of a CAD scheme sections previously developed in our research group. A computer model is proposed in order to compensate some flaws introduced in the digitization procedure. The purpose is assuring more uniformity to the digital mammography images, no matter the digitizer used. Tests with digital images from several different systems - since common equipment, with transparency adaptors, up to the most expensive and sophisticated, with laser scanning - by using the digitization driver proposed in this work have shown an increase in microcalcifications detection sensitivity for all cases relatively to the use of original digitized images without making use of the proposed model. Furthermore, the reduction in false positive rates was significant (from 70% up to 90%) in the same conditions. Therefore, the current application makes possible to any radiological institution the use of processing schemes to aid the detection and/or diagnosis of suspect structures in mammography, even using less sophisticated - and thus, with low cost - digitizers and keeping the performance quality.

Esta dissertação aborda o processo de implantação das tecnologias CAD/CADD nos escritórios de arquitetura no Brasil a partir dos anos 80, analisando avaliações já realizadas sobre estes programas, identificando também as necessidades da produção do projeto arquitetônico, estabelecendo critérios mínimos para o arquiteto escolher seu programa CAD/CADD. / To choose the CAD/CADD softwares is one of the gratest dificult that architects hava nodaways. The brazilian architects use these softwares since the 80's, but in the begginings the draws was a crafmanship because the real use of the software was still obscure. Decide for a software, its the real problem that architects have to face. Which one to use, how and way. This process is lone, hard and sometimes expensive. How to introduce the tecnology, analysing the evaluation that have been done about the architecture softwares of CADD and also identify the process, point the basic needs in an architect design is what this master science is about.

A indústria aeronáutica no Brasil tem se desenvolvido de modo acelerado em termos de desenvolvimento tecnológico e dos processos de fabricação aplicados. Com isso, tem se buscado melhores resultados durante o desenvolvimento do projeto e fabricação de aeronaves, visando uma melhor avaliação dos processos de fabricação, montagem, manutenção, confiabilidade e fatores humanos (ergonômicos). O intuito é aperfeiçoar a fabricação e simplificação da montagem dos conjuntos, de modo a facilitar a manufatura dos componentes que formarão o produto depois de acabado e tornar a montagem dos produtos aeronáuticos com o menor custo e da forma mais otimizada possível. Sendo assim, este trabalho visa o desenvolvimento de uma ferramenta que utiliza os conceitos de DFMA para aplicação específica no projeto e fabricação de aeronaves. O objetivo da ferramenta é auxiliar os engenheiros que atuam nas fases de desenvolvimento do avião, para que benefícios de facilidade de montagem possam ser alcançados com a utilização dos quadros de verificações. O trabalho inicia-se com a história da aviação, da indústria aeronáutica no mundo e no Brasil, e uma revisão teórica dos conceitos e princípios da metodologia DFMA. Em seguida é apresentado o ambiente da indústria aeronáutica, incluindo o processo de desenvolvimento integrado do produto, a implementação de projetos nestes segmentos e as fases de fabricação de uma aeronave. Na seqüência é apresentada a ferramenta de auxílio que foi desenvolvida em forma de quadros de análises, elaboradas com as regras e verificações a serem seguidas durante a criação do projeto, com o objetivo de consolidar os conhecimentos de manufatura e prevenir problemas futuros de montagem. Um estudo de caso é apresentado para evidenciar e comparar os resultados obtidos pela não aplicação efetiva dos conceitos da metodologia DFMA no desenvolvimento do projeto inicial, com os benefícios alcançados após a modificação do projeto baseado na aplicação dos conceitos de projeto para manufatura e utilização das tabelas. Por fim, os resultados são discutidos e a conclusão estabelecida. / Brazilian aeronautical industry has been developed faster and faster in terms of technology development and manufacturing processes. Thus, it has been planning to reach better results during the aircraft development and manufacturing phases, aiming to better evaluation of manufacturing processes, assembly, maintenance, capability and human factors (ergonomics). It is expected to improve the manufacturing and simplify the assembly to become easier the manufacturing of parts that will make the aircraft final assembly with low costs, high quality and the best optimized condition. So, the main objective of this study is to develop a guideline which uses the DFMA concepts for specific application on aircrafts design and manufacturing. The main goal of the guideline is to drive the engineers who work on aircraft development phases, about the manufacturing benefits that can be achieved when using the check list table of the guideline. This study starts with the aviation history and world and brazilian aeronautical industries and a theoretical review of the principles and concepts of the Design for Manufacturing and Assembly (DFMA) methodology. Next, the study describes the aeronautical industry environment, including the process of product integrated development, the implementation of projects in this sector and the airplane manufacturing phases. Subsequently, it has shown the guideline routine, which was developed in form of check list tables that contain rules and steps to be followed during the design creation and attempts to consolidate manufacturing knowledge and to prevent possible assemblies discrepancies. A case study is also presented to evident and makes the comparison between the results of aeronautical design that had been developed without DFMA concepts and post benefits reached after the project revision using the design for assembly concept and guideline tables. Finally, the results are discussed and the conclusion established.