Dissertations / Theses on the topic 'Scratch'
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Browning, Robert Lee. "Quantitative characterization of polymer scratch behavior using a standardized scratch test." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/5988.
Full textAbstract:
The lack of a widely-accepted quantitative methodology for evaluating the
scratch behavior of polymeric materials has resulted in the development and
establishment of a new methodology recently standardized as ASTM D7027-05. Using
a custom-built instrumented scratch machine, it is possible to produce controlled,
repeatable scratches on polymer surfaces under constant or linearly increasing loading
conditions at constant or increasing scratch rates. Software-aided digital image analysis
along with material science tools (SEM, OM, FTIR, etc.) allows polymer scratch
behavior to be analyzed without the ambiguity inherent in the past.
The current work will serve to describe the motivation for the development of
this methodology as well as illustrate the effectiveness of the increasing load/constant
rate test mode in three case studies. First, it will be shown that an acrylic coating on a
steel system exhibits three zones of scratch damage: adhesive delamination, transverse
cracking and finally buckling failure. It will be discussed how increases in ductility and
thickness serve to improve the scratch resistantance of this coating/substrate system.
Improvements in the scratch behavior of thermoplastic olefins (TPOs) through the use of surface-treated talc fillers and the slip agent erucamide will be shown in the second case.
It was found that the surface-treatment of the talc likely allows for enhanced migration
of the erucamide to the TPO surface, thus lowering the surface friction and greatly
increasing scratch resistance. Finally, the effects of processing conditions, namely
injection molding, on the scratch behavior of neat i-polypropylene will be represented by
the results of scratch tests conducted where the scratch direction was oriented both along
and transverse to the polymer melt flow direction. Based on the findings of the study,
there appears to be a high degree of surface anisotropy introduced to injection-molded
polymers due to complex fluid flow regimes as well as non-uniform cooling properties.
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Lim, Goy Teck. "Scratch behavior of polymers." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2720.
Full textAbstract:
This dissertation work is focused on the analytical and numerical examination of
the mechanical response of polypropylene (PP) under scratch deformation by a semispherical
indenter. The finite element (FE) method is employed as the analysis
technique and ABAQUS??, a commercial FE package is adopted to perform the analysis.
Important physical and computational considerations on the implementation of FE
analyses for the scratch problem are reviewed. It is shown through the discussion of the
generated results that a good understanding can be gained on how different scratch
conditions can affect scratch behavior of PP. A phenomenological deduction of the
scratch damage process and mechanisms is also established. Considering the two main
damage modes of polymers, shear yielding and crazing, it is shown that the two damage
modes not only exist in the scratch deformation, and moreover, that they may compete
against each other for dominance. A parametric study is also performed to assess the
influence of material and surface properties on scratch response of material.
A secondary research effort is also made to investigate the material constitutive
modeling of polymers. Focusing on elastomeric or rubbery materials, a new mixed network model between the Gaussian and eight-chain non-Gaussian models is proposed.
This mixed model inherently preserves the good predictive power of these two models
and yields better predictions over a wider range of deformation than that of the rubber
model adopted by ABAQUS??.
3
Pelillo, Enrico. "Scratch deformations of polymers." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286438.
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Varadi, Jasline Deepthi Das. "Scratch Behavior of Polystyrene." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1259183439.
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Stellato, Marco. "Horizon entropy from scratch." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6693/.
Full textAbstract:
Scopo di questo lavoro di tesi è lo studio di alcune proprietà delle teorie generali della gravità in relazione alla meccanica e la termodinamica dei buchi neri. In particolare, la trattazione che seguirà ha lo scopo di fornire un percorso autoconsistente che conduca alla nozione di entropia di un orizzonte descritta in termini delle carica di Noether associata all'invarianza del funzionale d'azione, che descrive la teoria gravitazionale in considerazione, per trasformazioni di coordinate generali. Si presterà particolare attenzione ad alcune proprietà geometriche della Lagrangiana, proprietà che sono indipendenti dalla particolare forma della teoria che si sta prendendo in considerazione; trattasi cioè non di proprietà dinamiche, legate cioè alla forma delle equazioni del moto del campo gravitazionale, ma piuttosto caratteristiche proprie di qualunque varietà rappresentante uno spaziotempo curvo. Queste caratteristiche fanno sì che ogni teoria generale della gravità possieda alcune grandezze definite localmente sullo spaziotempo, in particolare una corrente di Noether e la carica ad essa associata. La forma esplicita della corrente e della carica dipende invece dalla Lagrangiana che si sceglie di adottare per descrivere il campo gravitazionale. Il lavoro di tesi sarà orientato prima a descrivere come questa corrente di Noether emerge in qualunque teoria della gravità invariante per trasformazioni generali e come essa viene esplicitata nel caso di Lagrangiane particolari, per poi identificare la carica ad essa associata come una grandezza connessa all' entropia di un orizzonte in qualunque teoria generale della gravità.
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Cao, Lin, and Iina-Leena Lehtonen. "" You scratch my back, I'll scratch yours" : - Exportrådet och guanxi i dagens affärsliv." Thesis, Uppsala University, Department of Business Studies, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7561.
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Tsur, Moran. "Scratch Microworlds : introducing novices to scratch using an interest-based, open-ended, scaffolded experience." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112561.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 99-101).
Currently, many introductory coding activities for children focus on engaging them in solving puzzles. This thesis explores a different approach to introducing coding that engages children in creating projects based on their interests. I present the iterative design and testing of Scratch Microworlds, simplified versions of the Scratch coding environment that contain a small set of blocks for making projects based on a theme, such as dance, soccer, or music. I use a design-based research approach to iteratively design, implement and evaluate Scratch Microworlds. The design of Scratch Microworlds is guided by three questions: (1) how to simplify initial experiences while still supporting creativity, (2) how to provide scaffolding while maintaining learners' agency, and (3) how to provide starting points that spark rather than limit the imagination. This thesis describes the design process, and analyzes the results of user-testing with children and educators. It concludes with a set of guidelines for the design of newcomer experiences into coding that support children as creative thinkers, informed by constructionist learning theory.
by Moran Tsur.
S.M.
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Correia, Tânia Filipa Martins. "Scratch na aprendizagem da matemática." Master's thesis, Escola Superior de Educação, Instituto Politécnico de Setúbal, 2013. http://hdl.handle.net/10400.26/6568.
Full textAbstract:
Mestrado em Educação Pré-Escolar e Ensino do 1º Ciclo do Ensino BásicoEste trabalho apresenta um estudo, realizado no âmbito da Unidade Curricular Estágio III do ano letivo 2013/2014, que se desenvolveu com alunos do 4º ano de escolaridade de uma turma do 1º Ciclo do Ensino Básico. O seu principal objetivo é compreender as potencialidades do Scratch para a aprendizagem da Matemática e os constrangimentos que podem surgir durante a sua utilização na aula. Em particular, pretende-se perceber que ideias e conceitos matemáticos emergem no desenvolvimento de projetos com o Scratch, quais as potencialidades do Scratch para o estabelecimento de conexões matemáticas e que dificuldades surgem em atividades matemáticas que envolvam o Scratch. Trata-se de um estudo que visa compreender o envolvimento dos alunos na utilização de um recurso informático (o Scratch) para trabalhar a área da Matemática. Assim, no enquadramento teórico, procura-se clarificar o que se entende por aprender Matemática hoje e discutir o papel do Scratch no ensino e aprendizagem da Matemática. Em termos metodológicos, o estudo enquadra-se numa abordagem qualitativa de investigação e no paradigma interpretativo. Os dados foram recolhidos através da observação participante, recolha documental e entrevistas. Os resultados do estudo revelam que a grande maioria dos alunos esteve bastante interessada e envolvida em toda a atividade desenvolvida com o Scratch. Entre as razões para o seu interesse e envolvimento, estão a possibilidade de desenvolverem projetos em que tinham alguma autonomia e a oportunidade de partilharem questões/dúvidas bem como estratégias que utilizaram para as ultrapassar as suas dificuldades. Neste processo, consolidaram conhecimentos e compreenderam noções que ainda não tinham aprendido ou percebido até então. Além disso, vários alunos foram além daquilo que lhes foi solicitado como aconteceu, nomeadamente a propósito da “decoração” dos projetos e quando, na tentativa de programar a construção de alguns polígonos, descobriram como se desenham outros. Quanto às dificuldades experienciadas, houve algumas diferenças. Em geral, as maiores dificuldades foram a seleção dos comandos para a construção, no Scratch, dos dois primeiros polígonos regulares e a elaboração de registos escritos que descrevessem os raciocínios feitos. Estas dificuldades geraram, nalguns casos, uma desmotivação inicial que deixou de existir assim que os alunos começaram a compreender como se faziam as construções e os raciocínios que tinham de utilizar.
This report presents a study carried out under Stage III of the course of the school year 2013/2014, which is developed with a group of 4 th grade of the 1st cycle of elementary education. Its main objective is to understand the potentialities of Scratch for learning mathematics and the constraints that might arise during its use in the classroom. In particular, it aims to understand mathematical concepts and ideas that emerge in developing projects with Scratch, Scratch which potentialities for establishing mathematical connections and difficulties in mathematical activities involving Scratch. This is a study to understand the involvement of students in the use of a computer resource (Scratch) to work the area of mathematics. Thus, the theoretical framework, seek to clarify what is meant by learning mathematics today and discuss the role of Scratch in teaching and learning mathematics. In terms of methodology, the study was based on a qualitative research approach and on the interpretive paradigm. Data were collected through participant observation, interviews and document collection. The study results reveal that the vast majority of students was very interested and involved in any activity developed with Scratch. Among the reasons for their interest and involvement, are the capacity to develop projects where they had some autonomy and the opportunity to share questions/concerns and strategies they used to overcome their difficulties. In this process, the students consolidate knowledge and understand concepts that had not yet been able to realize until then. In addition, several students were beyond what they are asked for. This situation has arisen, in particular, concerning the "decoration" of projects and when, in an attempt to program the construction of some polygons, they figured out how to draw others. Regarding the difficulties experienced, there were some differences. In general, the main difficulties were the selection of commands for the construction in Scratch, of the first two regular polygons and the preparation of written records to describe their reasoning. These difficulties have generated, in some cases, an initial lack of motivation, which no longer exists as soon as the students began to understand how to do the constructions and the arguments they had to use.
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Bressan, Manuelle Lopes Quintas. "Scratch! um estudo de caso." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/2713.
Full textAbstract:
O estudo objetivou analisar como e se um Ambiente Visual de Programação pode contribuir apoiando os processos criativos de adolescentes, sendo uma ferramenta auxiliar para a aprendizagem pela solução de problemas, incitando novas formas de utilização das TIC na educação. O presente estudo justifica-se pela necessidade de aprofundar as questões relacionadas ao uso das TIC pelos docentes da Educação Básica e não apenas o uso de projetores e vídeos para substituir o quadro de giz, ou ferramentas de pesquisa em sites de busca apenas para transmitir informações de maneira a privilegiar as metodologias tradicionais de ensino. Como metodologia de pesquisa optou-se pela abordagem qualitativa de natureza interpretativa do tipo estudo de caso múltiplo. A apreensão dos dados foi em campo experimental por meio de questionário socioeducacional e diários de bordo, seguida da análise de conteúdos e descrição dos resultados obtidos. Os participantes do estudo foram adolescentes de 13 escolas públicas e privadas de Ensino Fundamental e do Ensino Médio no Município de Araucária-Pr. O estudo evidenciou o desenvolvimento das funções psicológicas superiores, pensamento computacional nos estudantes como atenção, memória e percepção. Estas habilidades foram observadas durante a elaboração dos projetos, por meio das habilidades de compreensão, planejamento, retrospecto e desenvolvimento de estratégias individuais e coletivas para a solução dos problemas encontrados. Este estudo se diferencia de outros já realizados com o Scratch, pois, enfatiza a busca da liberdade e criatividade dos sujeitos discentes na elaboração de projetos próprios, como estratégia para a autonomia.The study aimed to analyze how and if a Visual Programming Environment can contribute by supporting the creative processes of adolescents, an auxiliary tool for learning by problem solving, encouraging new ways of using ICT in education. This study is justified by the need to deepen the issues related to the use of ICT in Basic Education teachers and not only the use of projectors and videos to replace the chalkboard, or research tools in search engines only to convey information in order to favor traditional teaching methodologies. As a research methodology was chosen qualitative approach to interpretation, the study of case type. The seizure of the data was in experimental field through socio-educational and daily quiz board, followed by analysis of content and description of the results obtained. Study participants were adolescents from 13 public and private elementary schools and high school in the city of Araucaria-Pr. The study showed the development of higher psychological functions, computational thinking in students such as attention, memory and perception. These skills were observed during the preparation of projects, through the comprehension skills, planning, retrospect and development of individual and collective strategies to solve the problems encountered. This study differs from others already undertaken with Scratch therefore emphasizes the pursuit of freedom and creativity of the subjects students in developing their own projects, as a strategy for autonomy.
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Marrs, Jo-Ann. "Developing a Course from Scratch." Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etsu-works/7111.
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Cohen, Hagit Haya. "Textiled Becomings: Making from Scratch." Thesis, Griffith University, 2011. http://hdl.handle.net/10072/366908.
Full textAbstract:
Textiled Becomings is a creative work with an accompanying exegesis. This project explores
the ways in which cultural, social and environmental forces are intertwined in the creative
process, and examines how the final products reflect specific material processes and
embodied performative activities.
My creative work entails the production of living textiles ‘from scratch’: growing cotton from
seeds to make yarn, implanting the hand-spun yarn with barley seeds and weaving the seeded
yarns together using my body as a loom. No tools are involved in this process. Some of the
woven pieces take the shape of the space between the limbs of my body, while others take the
shape of the space between my limbs and those of another person, which together form the
loom. A selection of woven pieces will be hung in the gallery and irrigated to begin growing
and perform their life cycle in the final exhibition. This accompanying exegesis
contextualises the project and discusses particular issues pertaining to its development. The
exegesis begins by discussing a range of theoretical frameworks and their contribution to the
methodology that developed before examining my ability to correlate the material processes,
then looking at the embodied experience of making the work, which culminates in the
decision-making process involved in presenting the final exhibition.
Throughout the exegesis, I argue for the interdisciplinary/transdisciplinary nature of practiceled
research and creative practice. The Introduction establishes the context and importance of
weaving and textile work. I outline the way in which the exegesis should be considered in
relation to the creative work, emphasising that the two work together in tandem, and are
much greater and more far-reaching than the sum of their parts.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Humanities
Arts, Education and Law
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Damarla, Gowrisankar. "Determination of Wear in Polymers Using Multiple Scratch Test." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4627/.
Full textAbstract:
Wear is an important phenomenon that occurs in all the polymer applications in one form or the other. However, important links between materials properties and wear remain illusive. Thus optimization of material properties requires proper understanding of polymer properties. Studies to date have typically lacked systematic approach to all polymers and wear test developed are specific to some polymer classes. In this thesis, different classes of polymers are selected and an attempt is made to use multiple scratch test to define wear and to create a universal test procedure that can be employed to most of the polymers. In each of the materials studied, the scratch penetration depth s reaches a constant value after certain number of scratches depending upon the polymer and its properties. Variations in test parameters like load and speed are also studied in detail to understand the behavior of polymers and under different conditions. Apart from polystyrene, all the other polymers studied under multiple scratch test reached asymptotes at different scratch numbers.
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Rosenbaum, Eric (Eric Ross). "Jots : cultivating reflective learning in scratch." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/55197.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 121-123).
This thesis introduces the Jots system, a new technology designed to engage children in reflective learning as they work on design projects. Jots enables children to create brief updates, or "jots," describing their frustrations, achievements and other thoughts and feelings while creating projects in the Scratch programming environment. Later children can look back at their jots to reflect on their own design and learning processes. This thesis introduces an approach to reflective learning in four facets: cognitive, emotional, social and temporal. The design of the Jots system, as well as its development over time, are discussed. An empirical study with three middle school students who used jots in a facilitated context is analyzed in case studies and categorizations. The results of the study are examined in terms of the four aspects of reflection, and ideas for future work are presented.
by Eric Rosenbaum.
S.M.
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Mohan, Samarth. "Discovering the hidden users of Scratch." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/119730.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 52-54).
Usage statistics ("telemetry data") have become an essential tool for understanding how complex systems are used and how to improve them. However, many of these systems are deployed in areas with limited internet connectivity which hampers the ability to collect telemetry data. In this thesis, we describe a telemetry data collection system built for the Scratch programming language to collect usage data regarding how Scratch is being used in areas with poor internet connections. We develop the system to allow users to opt-in to sharing their usage and project data with the Scratch research team at the MIT Media Lab. The data is stored locally on the user's machine until it is ready to be transmitted. Once network conditions are appropriate, the packets are transmitted to a server which verifies the contents of the packet and stores it in a data storage cluster. We aggregate the data and build a visualization dashboard to examine usage patterns, geolocation statistics, and project content for Scratch users all around the world.
by Samarth Mohan.
M. Eng.
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Muhammad, Mansha. "Improving the scratch resistance of PMMA." Strasbourg, 2011. http://www.theses.fr/2011STRA6087.
Full textAbstract:
L'objectif de thèse était d'étudier le gain en résistance à la rayure apporté par ajout de plastifiants. L'hypothèse de départ était que l'on pouvait améliorer la résistance à la rayure en diminuant le coefficient de frottement. Les résultats expérimentaux confirment que les amides de différents acides gras sont efficaces en petites quantités pour réduire le coefficient de frottement sur surfaces de PMMA, et qu'un excès diminue ce bénéfice probablement en raison de leur effet « gommant « sur la surface. Les observations in-situ des aires de contact ont confirmé que la déformation moyenne lors du contact glissant est diminuée de manière significative pour les échantillons qui présentent le coefficient de frottement plus bas. Cette diminution du coefficient de frottement par les amides d'acides gras n'a pas pu être corrélée par le changement de l'énergie libre de surface du PMMA, et a été réalisée sans modifier le comportement volumique à l'échelle macroscopique comme à l'échelle submicronique. Il est supposé que le frottement est réduit par modification du comportement volumique seulement pour une très faible épaisseur non détectable par nana indentation. L'analyse mécanique du contact a montré que l'amélioration de la résistance à la rayure, quantifiable par un accroissement de l'angle de retour du contact, est clairement observée pour les contacts partiellement plastifiés. L'influence du coefficient de frottement dans le domaine du contact élastique comme pour les contacts largement plastifiés est presque négligeable. Dans le premier cas, la frontière entre domaine de contact élastique et élastoplastique est gouvernée uniquement par les propriétés mécaniques volumiques. Dans le second cas, la déformation géométrique du contact (directement liée la géométrie de la pointe) contrôle les déformations imposées au polymèreThe objective of thesis was to study the improvement of scratch resistance by using plasticizers. The aim in the beginning was that the improvement of the scratch resistance can be obtained as an effect of reduction of the coefficient of friction. The experimental results confirm that various fatty acid amides are effective only in small quantities to reduce the coefficient of friction of PMMA, and that an excess decrease this benefit because of their "gumming" effect on surface. This work showed and confirmed that the yielding at the contact is decreased significantly for the samples showing lower coefficient of friction. This reduction in the coefficient of friction by the fatty acid amides cannot be correlated with the change in surface free energy, and is without changing much the bulk behaviour at submicronic or macroscopic scale. Lt can be said that friction is reduced by modifying the bulk behaviour only for very low thickness which is not detectable by the nano indentation. The relation between the rear contact angle, contact strain, contact pressure and the coefficient of friction reveals that the maximum effect of coefficient of friction on the rear contact angle and the contact pressure is mainly during the plastic range of contact. The effect of coefficient of friction on rear contact angle during the elastic plastic and entirely plastic domain is almost negligible. As the plastic domain of the material depends mainly on the bulk mecanical properties: therefore to improve the scratch resistance of polymers, lt would be necessary to emphasize to modify the bulk behaviour of the materials
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KAUL, PAYAL. "SCRATCH RESISTANCE OF COATED FLOORING MATERIALS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1123268292.
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Jain, Parijat. "Prediction of aqueous solubility from SCRATCH." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/193517.
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Several methods have been proposed for the prediction of aqueous solubility. This study proposes the SCRATCH model for the aqueous solubility estimation of a compound directly from its structure. The algorithm utilizes predicted melting points and predicted aqueous activity coefficients for the solubility estimation, reflecting the truly predictive nature of the model. It uses two additive, constitutive molecular descriptors (enthalpy of melting and aqueous activity coefficient) and two non-additive molecular descriptors (symmetry and flexibility). The melting point prediction is trained on over 2200 compounds whereas the aqueous activity coefficient is trained on about 1640 compounds, making the model very rigorous and robust. The model is validated using a 10-fold cross- validation.A comparison with the General Solubility Equation suggests that the SCRATCH predicted aqueous solubilities have a slightly more average absolute error. This could result due to the fact that SCRATCH uses two predicted parameters whereas the GSE utilizes only one predicted property. Although the GSE is simpler to use, the drawback of requiring an experimental melting point is overcome in SCRATCH which can predict the aqueous solubility of a compound just based on its structure and no experimental values.
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Wong, Min Hao. "The development of scratch test methodology and characterization of surface damage of polypropylene." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1194.
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A new scratch test methodology is proposed. The new test methodology is
developed based on the principles of materials science and solid mechanics, which
include the consideration of material parameters, use of microscopy for image
analysis and the finite element method (FEM). The consistency and reproducibility of
test results are shown using a new scratch test device on two sets of neat and talcfilled
polypropylene (PP) systems. Three different test conditions, i.e., linear load
increase under constant rate, constant load under constant rate, and linear rate increase
under constant load, have been conducted to determine the most effective, informative
test conditions for evaluation of scratch resistance of polymers. Experimental
observations and FEM results show a good qualitative correlation. The unique
advantages of the new scratch test method for evaluating scratch resistance of
polymers are discussed. A systematic study of surface damage effected by a
progressive scratching load is performed on model polypropylene (PP) systems. Mar-scratch
and stress -whitening transitions can be readily observed, and the
corresponding critical loads determined. Distinctive scratch hardnesses and surface damage features are
found for different material systems. Visibility of scratched surface is quantified
using gray level analysis via a flatbed scanner and a commercial image analysis tool.
It is found that the onset of scratch visibility can be determined accurately and
reproducibly using the custom -built scratcher under progressive loading condition.
Talc particles are found to be responsible for the increased light scattering, leading to
greatly increased visibility. The observed scratch visibility is also found to be related
to the measured frictional force profiles. Approaches for producing scratch
resistant PP are discussed.
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Moghbelli, Ehsan. "Insights in fundamental scratch behavior of polymeric materials." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1941.
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Bujard, Bernard. "Hypotheses for Scratch Behavior of Polymer Systems that Recover." Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3153/.
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Scratch recovery is a desirable property of many polymer systems. The reason why some materials have demonstrated excellent scratch recovery while others do not has been a mystery. Explaining the scratch resistance based upon the hardness of a material or its crosslink density is incorrect.
In this thesis, novel polymers were tested in an attempt to discover materials that show excellent scratch recovery - one of the most important parameters in determining the wear of a material. Several hypotheses were developed in an attempt to give an accurate picture of how the chemical structure of a polymer affects its scratch recovery. The results show that high scratch recovery is a complex phenomenon not solely dependent upon the presence of electronegative atoms such as fluorine.
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Hwang, Ting-Hsiang Tony. "Exploring real-time video interactivity with Scratch." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/77018.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 40-41).
Real-time video interactivity is becoming increasingly popular in today's world with the advent of better and more affordable video input devices. With the recent release of the Microsoft Kinect followed by an official Kinect SDK, there has been an explosion of activity around utilizing this now easily-accessible video sensor data. Many creative uses have surfaced including object recognition, gesture recognition, and more. The audience capable of taking full advantage of these video technologies continues to be a technical crowd, likely with a background in computer science. But what if such video technology were made accessible to a much more diverse crowd? This thesis presents a set of computer vision tools for exploration of the real-time video interactivity space in the context of Scratch (scratch.mit.edu), a graphical block-based programming language accessible to all ages. To decide what functionality to provide to Scratch users, various computer vision algorithms are tested, including object detection, object recognition, face recognition and optical flow. Ultimately, an optical flow implementation is realized and its generative abilities are observed through testing with different user groups.
by Ting-Hsiang Tony Hwang.
M.Eng.
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Wang, Peng-zhu. "Investigation of scratch damage on polymer materials." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620732.
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Gorbatyuk, K. S. "Can we create a human from scratch?" Thesis, Сумський державний університет, 2012. http://essuir.sumdu.edu.ua/handle/123456789/28686.
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Do you know who Frankenstein is? Probably yes, but I would like to remind you. Victor Frankenstein is the protagonist of the novel, Mary Shelley's "Frankenstein or the Modern Prometheus." In the novel, Victor Frankenstein is a young student from Geneva.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/28686
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Khatib, Jamal F. "Mineral-filled polypropylene: Improvement of scratch resistance." Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc3009/.
Full textAbstract:
A potential alternative to acrylonitrile-butadiene-styrene (ABS) and polycarbonate+ABS (PC+ABS), pigmented mineral-filled polypropylene (PP) finds an opening in automotive interior components such as instrument panels, knee bolsters, consoles, etc. Because of the lack of surface aesthetics, pigmented mineral-filled PP is experiencing a limitation to its acceptance in many applications. This study focuses on exploring various mineral fillers and additives in polypropylene to provide a material with enhanced scratch resistance. Several physical properties including Rockwell and Shore D hardness are investigated, and it is determined that Filler W improves scratch resistance. It is also determined that Filler T-filled-PP has poor scratch resistance even with the addition of a lubricant.
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Fullick, Julia. "You Scratch My Back and I'll Scratch Yours: Mentor-Perceived Costs and Benefits and the Functions They Provide Their Proteges." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2278.
Full textAbstract:
Mentoring relationships can have both costs and benefits for mentors and their proteges. The present research examined the degree to which mentors' perceived costs and benefits affect the functional and dysfunctional mentoring they provide to their proteges. Additionally, I investigated whether mentor-perceived costs and benefits were associated with the mentors' own goal orientation and the goal orientation of their proteges. Data were collected from 86 proteges and their current supervisory mentors. Consistent with expectations, when mentors reported greater costs of embarrassment associated with their relationship, the proteges reported receiving greater dysfunctional mentoring. Proteges who reported receiving greater functional mentoring tended to have mentors who perceived greater benefits of mentoring them. Both proteges and mentor goal orientations demonstrated significant correlations with mentor-perceived costs and benefits of their relationships. Implications for training and reinforcing functional mentoring will be discussed.M.S.
Department of Psychology
Sciences
Industrial Org Psychology MS
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Ventorini, André Eduardo. "CONSTRUÇÃO DE RELAÇÕES FUNCIONAIS ATRAVÉS DO SOFTWARE SCRATCH." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/6756.
Full textAbstract:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis dissertation presents the delineation of a research for Master's Degree involving students of the first year of High School, which has the objective of analyzing the potentialities of the software Scratch for the elaboration of learning objects in the construction process of functional relationships involving functions. This is a qualitative research. The activities developed deal with the idea of function, inverse function and Cartesian Plane and were dynamized with three groups of students at a school in the city of Santa Maria/RS. As theoretical support it was adopted the Theory of Conceptual Fields of Gerard Vergnaud and the Theory of Constructionism developed by Seymour Papert due to the important role for the study of cognitive functioning of the subjects- in-situation and the contribution of the computer in the comprehension of Mathematical concepts. In order to promote the construction of functional relationships, activities have been planned with the use of the Scratch software, allowing the student to perform several trials involving concepts of function. The results show that the use of the Scratch for learning functions enables students to make deductions, anticipations, control results, conclusions, assisting in the formalization and abstraction of these concepts, when inserted into an environment of resolution of situations and research.
Esta dissertação apresenta o delineamento de uma pesquisa de mestrado envolvendo alunos do primeiro ano do Ensino Médio, a qual tem por objetivo analisar as potencialidades do software de programação Scratch na elaboração de objetos de aprendizagem no processo de construção das relações funcionais envolvendo funções. Trata-se de uma pesquisa de cunho qualitativo. As atividades elaboradas versam sobre a ideia de função, função inversa e o plano cartesiano e foram dinamizadas junto a três turmas de alunos de uma escola da cidade de Santa Maria/RS. Como aporte teórico adota-se a Teoria dos Campos Conceituais de Gerard Vergnaud e a Teoria do Construcionismo de Seymour Papert devido ao papel importante no estudo do funcionamento cognitivo do "sujeito-em-situação" e da contribuição do computador na compreensão dos conceitos matemáticos. Com o intuito de propiciar a construção das relações funcionais, as atividades foram planejadas com o uso do software Scratch, permitindo que o aluno realize diversas experimentações envolvendo conceitos da função. Os resultados apontam que a utilização do Scratch para a aprendizagem de funções oportuniza ao aluno fazer deduções, antecipações, controlar resultados, tirar conclusões, auxiliando na formalização e abstração desses conceitos, quando inserido em um ambiente de resolução de situações e investigação.
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Parry, Glenn Charles. "Scratch resistant coatings produced by sol-gel techniques." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620938.
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Hilbig, Travis. "Scratch Modeling of Polymeric Materials with Molecular Dynamics." Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc149608/.
Full textAbstract:
It is impossible to determine the amount of money that is spent every replacing products damaged from wear, but it is safe to assume that it is in the millions of dollars. With metallic materials, liquid lubricants are often used to prevent wear from materials rubbing against one another. However, with polymeric materials, liquid lubricants cause swelling, creating an increase in friction and therefore increasing the wear. Therefore, a different method or methods to mitigate wear in polymers should be developed. For better understanding of the phenomenon of wear, scratch resistance testing can be used. For this project, classic molecular dynamics is used to study the mechanics of nanometer scale scratching on amorphous polymeric materials. As a first approach, a model was created for polyethylene, considering intramolecular and intermolecular interactions as well as mass and volume of the CH2 monomers in a polymer chain. The obtained results include analysis of penetration depth and recovery percentage related to indenter force and size.
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WIRASATE, SUPA. "SCRATCH BEHAVIOR OF POLY(carbonate) FILM/SUBSTRATE SYSTEMS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1131995339.
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CHAKRAVARTY, SRINIVAS L. N. "DEVELOPMENT OF SCRATCH RESISTANT PECVD SILICA-LIKE FILMS." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin973542599.
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Krupicka, Andreas. "Use and interpretation of scratch tests on organic coatings." Doctoral thesis, KTH, Polymer Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3357.
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Wang, Xueqin. "Characterization of scratch and mar resistance of automotive clearcoats." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/8695.
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Bard, Romain (Romain M. ). "Analysis of the scratch test for cohesive-frictional materials." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61521.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (p. 143-148).
In this thesis we develop analytical solutions for the relations between scratch hardness and strength properties of cohesive-frictional materials of the Mohr-Coulomb and Drucker-Prager type. Based on the lower-bound yield design approach, closed form solutions are derived for frictionless scratch devices, and validated against computational upper bound and elastoplastic Finite Element solutions. The influence of friction at the blade{material interface is also investigated, for which a simple computational optimization is proposed. The model is extended to porous cohesive-frictional materials through the use of a homogenized strength criterion based on the Linear Comparison Composite theory. Relations between scratch hardness, porosity and strength properties are proposed in the form of fitted functions. Illustrated for scratch tests on cement paste, we show that the proposed solutions provide a convenient way to determine estimates of cohesion and friction parameters from scratch data, and may serve as a benchmark to identify the relevance of strength models for scratch test analysis.
by Romain Bard.
S.M.
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Kareer, Anna. "Nano-scratch hardness and the Lateral Size Effect (LSE)." Thesis, University of Leicester, 2015. http://hdl.handle.net/2381/31844.
Full textAbstract:
Nano-scratch testing has been used throughout this thesis in order to deepen the understanding of the processes occurring during the nano-scratch test, and to develop a method for calculating the nano-scratch hardness, from the quantifiable variables that are obtainable from the technique. Scratch testing on the macro scale is a well-established technique, however when reducing the scale of a mechanical test, whilst interest is focussed on the yield strength or hardness of the material, plasticity size effects must be explored. A literature survey concludes that size effects in nano-scratch testing have not been investigated in the past, thus this is the main subject of this thesis. In order to carry out this investigation a number of methods were trialled to calculate the nano-scratch hardness of pure, polycrystalline, oxygen free copper using both the edge forward and the face forward tip orientations of a diamond Berkovich indenter. The results obtained were compared to the indentation hardness and the most theoretically suitable method was adopted for later experiments carried out in this work; the technique for obtaining measurements was optimised, such that a genuine lateral size effect (LSE), whereby the nano-scratch hardness increases with decreasing scratch size, was observed. To further investigate the lateral size effect, nano-scratches were performed on a sample of single crystal copper in different work hardened states. It was observed that the nano-scratch hardness not only increases with decreasing scratch size, but also increases when the spacing between the dislocations in the material is reduced; when the level of work hardening in the sample increases, the density of dislocations increases, thus the spacing between these obstacles is reduced. In addition to this, the anisotropy of the nano-scratch hardness was investigated by altering the scratch direction in the (100) plane of the single crystal copper. It was found that the nano-scratch hardness is anisotropic and that the scratch hardness is largest when the scratch direction is parallel to the slip plane. It is known that the yield strength of a material increases with decreasing average grain size and therefore the effect of grain size on the nano-scratch hardness was considered. By reducing the grain size of pure, annealed, oxygen free copper, the nano-scratch hardness was observed to increase. In all experiments, the nano-scratch hardness values of scratches performed in the face forward tip orientation were larger than that of scratches performed in the edge forward tip orientation, when scratching the same sample condition. This suggests that scratch hardness is tip geometry dependent and in order to develop a method of calculating a tip orientation-independent scratch hardness, the shape of the indenter and the plastic flow of material around the indenter in that orientation, must be known and incorporated into the calculation, possibly as a drag coefficient. In addition to the geometry of the plastic flow, and therefore the plastic zone size, it was found that the nano-scratch hardness is also governed by the interaction between the geometry of the indenter and the grain boundaries in the material. Finally a number of experimental issues from the nano-scratch test are highlighted and researchers are encouraged to consider these precautions when using the nano-scratch test.
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Abdalla, Lena(Lena A. ). "Classification of computer programs in the Scratch online community." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/129862.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, February, 2020Cataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 133-136).
Scratch is a graphical programming platform that empowers children to create computer programs and realize their ideas. Although the Scratch online community is filled with a variety of diverse projects, many of these projects also share similarities. For example, they tend to fall into certain categories, including games, animations, stories, and more. Throughout this thesis, I describe the application of Natural Language Processing (NLP) techniques to vectorize and classify Scratch projects by type. This effort included constructing a labeled dataset of 873 Scratch projects and their corresponding types, to be used for training a supervised classifier model. This dataset was constructed through a collective process of consensus-based annotation by experts. To realize the goal of classifying Scratch projects by type, I first train an unsupervised model of meaningful vector representations for Scratch blocks based on the composition of 500,000 projects. Using the unsupervised model as a basis for representing Scratch blocks, I then train a supervised classifier model that categorizes Scratch projects by type into one of: "animation", "game", and "other". After an extensive hyperparameter tuning process, I am able to train a classifier model with an F1 Score of 0.737. I include in this paper an in-depth analysis of the unsupervised and supervised models, and explore the different elements that were learned during training. Overall, I demonstrate that NLP techniques can be used in the classification of computer programs to a reasonable level of accuracy.
by Lena Abdalla.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
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Atroshenkova, Anastasiia, and Анастасія Олександрівна Атрошенкова. "Strength properties investigation of glass by scratch test method." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/54160.
Full textAbstract:
Робота публікується згідно наказу Ректора НАУ від 27.05.2021 р. №311/од "Про розміщення кваліфікаційних робіт здобувачів вищої освіти в репозиторії університету". Керівник роботи: доцент, к.т.н. Закієв Вадим ІсламовичThis master thesis is dedicated to the сomparative study of glass strength using scratch test technique. The methods of investigation are scratch tests, nanoindentation and calculation methods for results analysis.
Ця магістерська робота присвячена порівняльному вивченню міцності скла за допомогою методики випробування дряпанням. Методами дослідження є скретч-тести, наноіндентування та розрахункові методи аналізу результатів.
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Dasari, Aravind. "On toughening and wear/scratch damage in polymer nanocomposites." Thesis, The University of Sydney, 2007. http://hdl.handle.net/2123/1911.
Full textAbstract:
The drastic improvements in stiffness and strength even with the addition of small percentage of clay to a polymer are commonly traded-off with significant reductions in fracture toughness. It is believed that the presence of a stiff nano-filler will restrict the mobility of the surrounding matrix chains, and thus limit its ability to undergo plastic deformation, thereby decreasing their fracture toughness. To understand the role of rigid nano-fillers, like clay and their constraint effect on the surrounding polymer matrix, the effects of preferentially organized polyamide 6 lamellae in the vicinity of organoclay layers on the toughening processes are studied and compared with polyamide 6 filled with an elastomeric additive (POE-g-MA). It is suggested that to impart high toughness to polymer/organoclay nanocomposites, full debonding at the polymer-organoclay interface is necessary so that shear yielding of large volumes of matrix material can be enhanced. However, due to the strong tethering junctions between the individual organoclay layers and the matrix, full-scale debonding at the polymer-organoclay interface is rarely observed under stress conditions indicating that the constraint on the polymer adjacent to the clay is not relieved. Therefore, this has led to the development of ternary nanocomposites by adding a soft elastomeric dispersed phase to polymer/clay systems to obtain well-balanced mechanical properties. Polyamide 66/SEBS-g-MA/organoclay nanocomposites are prepared with four different blending protocols to understand the effect of blending protocol on the microstructure, mechanical properties and fracture mechanisms of the ternary nanocomposites so as to obtain new insights for producing better toughened polymer nanocomposites. In general, it is found that the level of enhancement of fracture toughness of ternary nanocomposites depends on: (i) the location and extent of dispersion of organoclay and (ii) the internal cavitation of rubber particles leading to effective relief of crack-tip tri-axial constraint and thus activating the matrix plastic deformation. Based on the wear/scratch damage studies on different polymer nanocomposite systems, it is suggested that elastic modulus and toughness of polymer nanocomposites are not the predominant factors controlling the material removal or friction coefficient and cannot be the sole indicators to compare and rank candidate materials. It is also found that nano-fillers by themselves, even if uniformly dispersed with good interfacial interaction with the matrix, do not irrevocably improve the wear (and friction) properties. Although it is important to consider these factors, it is necessary to thoroughly understand all microstructural parameters and their response to wear/scratch damage. Other important factors that should be considered are the formation of a uniform and stable transfer film on the counterface slider and the role of excessive organic surfactants or other modifiers added to disperse nanoparticles in a polymer matrix. It is also emphasized that the mechanisms of removal of materials during the wearing/scratching process should be studied meticulously with the use of high resolution microscopic and other analytical tools as this knowledge is critical to understand the surface integrity of polymer nanocomposites.
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Dasari, Aravind. "On toughening and wear/scratch damage in polymer nanocomposites." University of Sydney, 2007. http://hdl.handle.net/2123/1911.
Full textAbstract:
Doctor of PhilosophyThe drastic improvements in stiffness and strength even with the addition of small percentage of clay to a polymer are commonly traded-off with significant reductions in fracture toughness. It is believed that the presence of a stiff nano-filler will restrict the mobility of the surrounding matrix chains, and thus limit its ability to undergo plastic deformation, thereby decreasing their fracture toughness. To understand the role of rigid nano-fillers, like clay and their constraint effect on the surrounding polymer matrix, the effects of preferentially organized polyamide 6 lamellae in the vicinity of organoclay layers on the toughening processes are studied and compared with polyamide 6 filled with an elastomeric additive (POE-g-MA). It is suggested that to impart high toughness to polymer/organoclay nanocomposites, full debonding at the polymer-organoclay interface is necessary so that shear yielding of large volumes of matrix material can be enhanced. However, due to the strong tethering junctions between the individual organoclay layers and the matrix, full-scale debonding at the polymer-organoclay interface is rarely observed under stress conditions indicating that the constraint on the polymer adjacent to the clay is not relieved. Therefore, this has led to the development of ternary nanocomposites by adding a soft elastomeric dispersed phase to polymer/clay systems to obtain well-balanced mechanical properties. Polyamide 66/SEBS-g-MA/organoclay nanocomposites are prepared with four different blending protocols to understand the effect of blending protocol on the microstructure, mechanical properties and fracture mechanisms of the ternary nanocomposites so as to obtain new insights for producing better toughened polymer nanocomposites. In general, it is found that the level of enhancement of fracture toughness of ternary nanocomposites depends on: (i) the location and extent of dispersion of organoclay and (ii) the internal cavitation of rubber particles leading to effective relief of crack-tip tri-axial constraint and thus activating the matrix plastic deformation. Based on the wear/scratch damage studies on different polymer nanocomposite systems, it is suggested that elastic modulus and toughness of polymer nanocomposites are not the predominant factors controlling the material removal or friction coefficient and cannot be the sole indicators to compare and rank candidate materials. It is also found that nano-fillers by themselves, even if uniformly dispersed with good interfacial interaction with the matrix, do not irrevocably improve the wear (and friction) properties. Although it is important to consider these factors, it is necessary to thoroughly understand all microstructural parameters and their response to wear/scratch damage. Other important factors that should be considered are the formation of a uniform and stable transfer film on the counterface slider and the role of excessive organic surfactants or other modifiers added to disperse nanoparticles in a polymer matrix. It is also emphasized that the mechanisms of removal of materials during the wearing/scratching process should be studied meticulously with the use of high resolution microscopic and other analytical tools as this knowledge is critical to understand the surface integrity of polymer nanocomposites.
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Kurkcu, Pinar. "Modification Of Polypropylene Films For Antistatic And Anti-scratch Properties." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12609067/index.pdf.
Full textAbstract:
Polypropylene films are widely used in industry, especially for packaging purposes.
However, these films become statically charged when they are subject to friction.
The accumulation of charges in some applications can be harmful, especially for the
electronic devices and can cause undesirable appearance due to the attraction of
dusts. Furthermore, minimum susceptibility to mechanically induced surface
damage is a desired property since scratches reduce the mechanical strength and the
bright texture of the film in packaging of commercial items and limit the
applications of the material.
This study aims to provide antistatic character to polypropylene films by the
utilization of conductive fillers which function independent of humidity and enhance
their scratch resistance by means of aromatic based additives.
Polypyrrole-polypropylene composites including 2%, 5%, 7% and 9% pyrrole were
synthesized by chemical modification. 2% of pyrrole was adequate to provide
antistatic character to the films. Moreover, they attained conductive property when
the pyrrole content exceeds 7%.
Polypropylene based materials containing four different compositions of
1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, pphenylene
diamine and hydroquinone were prepared by mechanical mixing. Scratch
resistance of polypropylene films increased significantly with the insertion of
additives. The material containing 2% 1,7-dihydroxynaphthalene introduced the
highest enhancement by more than 60%. Moreover, mechanical analysis results
showed that insertion of the additives except hydroquinone increased Young’
s modulus of the polypropylene films. In addition, tensile strength and elongation at break of polypropylene films were enhanced significantly with insertion of the additives regardless of the additive type.
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Dyrda, Katia Marjolaine. "Adhesion characterization of hard ceramic coatings by the scratch test." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ37948.pdf.
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Dominguez, Angel. "Heap data allocation to scratch-pad memory in embedded systems." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/6721.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Gregg, Elizabeth A. "Teaching Critical Media Literacy Through Videogame Creation in Scratch Programming." Thesis, Loyola Marymount University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3638178.
Full textAbstract:
Critical media literacy (Kellner & Share, 2005) may better equip children to interpret videogame content and to create games that are nonviolent and socially just. Videogames are growing in popularity in classrooms. Yet educators and parents have concerns about the violent and stereotypical content they include. An earlier study based on the curriculum Beyond Blame: Challenging Violence in the Media (Webb, Martin, Afifi, & Kraus, 2009) examined the value of a media awareness curriculum. In this mixed-method study, I explored the effectiveness of a critical media literacy program that incorporated collaboratively creating nonviolent or socially-just games in teaching fourth-grade students the factors of awareness of violence, marketing, and critical media literacy. Qualitative data collected from teacher reflection notes, student journals, Scratch projects, and interviews revealed the positive effects of the program. Quantitative data supported these conclusions. This highlights the need for schools to engage students in computer programming as a means to learn academics, while educating students in critical media literacy to better enable them to navigate wisely the media saturated world in which they live. In learning programming, students engage in collaborative work, their interactions helping them to collectively create meaning for the symbols they create. Set in a framework of critical media literacy and symbolic interactionism (Blumer, 1969; Mead, 1934), this study provides an innovative model for teaching computer programming and critical media literacy skills to students.
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Chen, Rita. "ScratchStats : a site for visualizing and understanding scratch usage data." Thesis, Massachusetts Institute of Technology, 2010. http://scratch.mit.edu.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 65-66).
This thesis introduces ScratchStats, an extension to the Scratch website where users can view and understand Scratch usage data through a series of interactive visualizations. Scratch is a visual programming language that makes it easy to create interactive stories, games, and artwork. Accompanying the Scratch application is the Scratch Online Community, a website that allows users to upload and share their creations. The visualizations created in this thesis describe community, personal, and network statistics. ScratchStats aims to provide answers to questions about Scratch usage, promote reflection and introspective learning, and aid in teaching data literacy.
by Rita Chen.
M.Eng.
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Wyrobnik, David J. (David Joseph). "Design and implementation of search for the Scratch Online Community." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106393.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 52).
The Scratch Online Community has been experiencing rapid growth and has around 9.5 million users and 12.5 million shared projects today. This exponential growth introduces a need for a new Search infrastructure that will enable users to find and discover more relevant projects, while allowing the Scratch team to control the ranking of search results. This thesis presents a complete Search system that will be deployed on the Scratch website and a novel visual tool named FIRST (Fast Iterative Relevance Search Tool) that aids in the process of defining a useful relevance function for Search.
by David J. Wyrobnik.
M. Eng.
45
Gregg, Elizabeth Anne. "Teaching Critical Media Literacy Through Videogame Creation in Scratch Programming." Digital Commons at Loyola Marymount University and Loyola Law School, 2014. https://digitalcommons.lmu.edu/etd/199.
Full textAbstract:
Critical media literacy (Kellner & Share, 2005) may better equip children to interpret videogame content and to create games that are nonviolent and socially just. Videogames are growing in popularity in classrooms. Yet educators and parents have concerns about the violent and stereotypical content they include. An earlier study based on the curriculum Beyond Blame: Challenging Violence in the Media (Webb, Martin, Afifi, & Kraus, 2009) examined the value of a media awareness curriculum. In this mixed-method study, I explored the effectiveness of a critical media literacy program that incorporated collaboratively creating nonviolent or sociallyjust games in teaching fourth-grade students the factors of awareness of violence, marketing, and critical media literacy. Qualitative data collected from teacher reflection notes, student journals, Scratch projects, and interviews revealed the positive effects of the program. Quantitative data supported these conclusions. This highlights the need for schools to engage students in computer programming as a means to learn academics, while educating students in critical media literacy to better enable them to navigate wisely the media saturated world in which they live. In learning programming, students engage in collaborative work, their interactions helping them to collectively create meaning for the symbols they create. Set in a framework of critical media literacy and symbolic interactionism (Blumer, 1969; Mead, 1934), this study provides an innovative model for teaching computer programming and critical media literacy skills to students.
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Beug, Anne. "Teaching Introductory Programming Concepts: A Comparison of Scratch and Arduino." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/778.
Full textAbstract:
Computing has become an integral part of modern America. The Bureau of Labor Statistics estimates that between 2008 and 2018, the United States will have 1.4 million job openings in computing fields [1]. Since the early 2000's (just after the "dot com bust"), the number of students enrolled in computing majors (Computer Science, Computer Engineering, etc.) dropped precipitously by over 50%, only starting to rise again in 2009 [2]. One way to rectify to this gap between demand and supply is to start training students in computational thinking during high school. While the Computer Science Advanced Placement AB test has been retired, a new AP test called "CS Principles" has been added to the suite of tests [3], highlighting the importance of computing to a modern education. Not only will we need more computing professionals, people in other professions will need to have computing skills. We propose in this thesis a comparison of two computing platforms. Scratch is a well-proven platform that teaches core programming concepts through a graphical programming interface. Arduino boards are open-source microcontrollers with an accompanying development environment and C-like language. We develop a parallel curriculum in Scratch and Arduino and compare the two. While we are unable to draw conclusive results from our quantitative study, from our qualitative research we see that Arduino is unsuitable for teaching core programming concepts to computing novices.
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Udayakumaran, Sumesh. "Compiler-decided dynamic memory allocation for scratch-pad based embedded systems." College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3789.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2006.Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Takase, Hideki, Hiroyuki Tomiyama, and Hiroaki Takada. "Allocation of scratch-pad memory in priority-based multi-task systems." IEEE, 2009. http://hdl.handle.net/2237/13970.
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Graves, Christopher Marten-Ellis. "Scratching with all your fingers : exploring multi-touch programming in Scratch." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91816.
Full textAbstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 79-80).
Since the introduction of the iPhone in 2007, many millions of people have used a multi-touch interface; but, due to the inaccessibility of most tablet software development kits, very few of these people have ever developed their own multi-touch interactions. This thesis discusses the challenges in developing a toolkit that allows novices to easily make simple touch-interactive projects, while simultaneously empowering experienced users to create complex, personalized multi-touch interactions. Three potential toolkit designs are presented and evaluated using the principle of "low floors, wide walls, and high ceilings." The toolkits presented have been developed within the context of an upcoming tablet version of Scratch, which aims to allow users of all ages and educational backgrounds (but school-aged children in particular) to easily make and share their own stories, games, and animations on and for the tablet.
by Christopher Marten-Ellis Graves.
M. Eng.
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Rodeghiero, Carolina Campos. "Aprendizagem conectada em modos de participação no Scratch: proposta de tipologia." Universidade Catolica de Pelotas, 2016. http://tede.ucpel.edu.br:8080/jspui/handle/tede/600.
Full textAbstract:
Submitted by Cristiane Chim (cristiane.chim@ucpel.edu.br) on 2017-05-22T14:11:11Z
No. of bitstreams: 1
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Learning what seems relevant to the academic formation deserves the constant scientific investigation for the world we live in. Today, communication technologies are a part of the personal and professional lives of adults and youth in ways never seen before. The formal education environment, on the other hand, doesn’t look into the same technologies as allies to the classroom learning, and so many times builds a wall between communication tools that students love to use and their scholar curriculum. Considering the necessity of discussion on learning in informal environments, this thesis was made with the goal of bringing to the surface, using educational studies for this context, a learning model for discussions in online forums. To accomplish that, we present the case of Scratch, a tool used for the creation of projects through blocks language, from computer science. Using Scratch’s online discussion forums, we collected data from its participants’ conversations, and visualized the data using Social Network Analysis (SNA) tools to see these groups’ content and members as a network. Our research corpus consists of data from eight (8) online forums, collected in two moments: August and September 2015; and again in August and September of 2016. Later, we did the data analysis: first the network one, highlighting who were the most influential participants in the forums and what roles they have played on it; and then, by the content analysis, it was possible for us to understand the subjects that users talked about most, and also to see the frequency of word pairs appeared in the discussions. As a contribution to the first two analyses, we’ve clipped 20 messages found in our corpus data as a complement to the understanding of data context. Finally, we based our thesis on the Connected Learning theories (ITO ET AL, 2013) to point in the results what can be like this considered in the actors relations. Composing the final purpose of this research, we propose the connected learning model in Scratch, creating a typology for its members’ ways of participation. In the end, we suggest new ways of participation that might be applied to Scratch or other communities so it can direct its members’ activities to a learning model based on social interactions.
Aprender informalmente o que é relevante à formação acadêmica merece o constante aprofundamento científico necessário ao contexto em que vivemos atualmente. Hoje, as tecnologias de comunicação fazem parte da vida pessoal, escolar e profissional de adultos, jovens e crianças como jamais o foi anteriormente. O ambiente escolar formal, no entanto, não busca nas mesmas tecnologias aliados para trabalhar a aprendizagem em sala de aula, e muitas vezes constrói um muro entre as ferramentas de comunicação que os alunos têm prazer em utilizar e o currículo escolar. Considerando a necessidade de discussão sobre aprendizagens em ambientes informais, esta tese foi realizada objetivando trazer à tona, observando estudos sobre a educação nesses contextos, um modelo de aprendizagem em fóruns de discussão online. Para isso, apresentamos o caso do Scratch, uma ferramenta utilizada para a criação de projetos por meio da programação em linguagem de blocos, utilizada na computação. Considerando os fóruns online do Scratch, extraímos dados de conversações realizadas por seus participantes, e os configuramos enquanto grafos por meio de ferramentas da Análise de Redes Sociais (ARS), para observarmos a constituição desses grupos enquanto rede e no que se refere ao conteúdo das conversações ali expostas. Por corpus do estudo, selecionamos dados de oito (8) fóruns, coletados em dois momentos: agosto e setembro de 2015; e, em 2016, no mesmo período, passado um ano da primeira coleta. Posteriormente, realizamos a análise dos dados, primeiramente com a análise de redes, destacando quais foram os participantes mais influentes nos fóruns e o papel que desempenharam. Já pela análise de conteúdo foi possível entender os temas mais abordados pelos usuários, sua continuidade ou desistência, e as co-ocorrências de palavras existentes nessas discussões. Em contribuição às duas primeiras formas de análise, buscamos em 20 recortes de mensagens nos fóruns integrantes do corpus o complemento para compreendermos o contexto dos dados. Finalmente, nos baseamos nas teorias da Aprendizagem Conectada (ITO ET AL, 2013) para apontar nos resultados o que pode ser constituído como tal nas interações entre os sujeitos da pesquisa. Constituindo a proposta final deste trabalho, propomos o modelo de aprendizagem conectada do Scratch, criando para isso uma tipologia dos modos de participação de seus integrantes. No fechamento, sugerimos, ainda, novos modos de participação que podem ser aplicados ao Scratch para que o mesmo direcione as atividades de seus integrantes à aprendizagem baseada em interações sociais.