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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

WELD READ-THROUGH DEFECTS IN LASER TRANSMISSION WELDING

Cao, Xiaochao 02 July 2010 (has links)
In laser Transmission Welding (LTW), the laser beam passes through the transparent part and is dissipated as heat in the absorbent material through the use of laser-absorbing pigments such as carbon black (CB). This energy is then conducted further into both parts. Melting and subsequent solidification occur at the interface causing a weld to form between the two parts. Gluing or welding structures to the back of automotive Class-A panels often results in the appearance of undesirable surface deformations on the Class-A side. Through control of the laser welding and material parameters, it may be possible to use contour LTW as a means of joining structures to the back of absorbent Class-A panels without creating these unwanted surface defects. A series of lap welds was made using a range of CB levels, laser powers and polypropylene part thicknesses. A profilometer was used to measure the size and shape of the defects generated on the surface of the black part. Two types of defects were observed: ribs and sink marks. It was observed that lower powers combined with higher carbon black levels generally resulted in smaller defects. The type of defect depended on the boundary conditions between the two parts and the flow of polymer that had thermally expanded during welding (flash). If weld flash flowed into gaps between the two plates, rib defects were always observed. If flash flowed elsewhere and no gaps existed between the plates, sink marks occurred. Finite element modeling was used to qualitatively validate these observations. / Thesis (Master, Chemical Engineering) -- Queen's University, 2010-07-02 14:34:41.201
52

Teacher read aloud: exploring an educational tradition through a social practice framework

Boyd, Karen 14 January 2014 (has links)
Teacher read aloud is perceived as a long-standing, common classroom practice. The purpose of this study was to examine this educational tradition in a framework of literacy as social practice that supports the ideas of apprenticeship, discourse communities, and specific contextual-discipline literacies. Using mixed-methods, data was gathered on three major components of teacher read aloud practice: (1) time spent on read aloud, (2) purpose and text choice of read aloud, (3) and practices that focused on developing literary understanding through read aloud. Through these components, the knowledge and beliefs of teachers regarding teacher read aloud, literacy and literary development, and children’s literature were examined. Data was gathered through an online survey, logbooks, and interviews. Statistical and deductive analysis of the data’s quantitative components was conducted; and interview and open-survey responses were qualitatively analyzed. Analysis of the data on purpose and text choice suggests children’s literature is being read aloud in classrooms in ways that may conflate the literacy and literary development of students, and these ways may model particular types of values and behaviours when reading. Multiple purposes were identified for read alouds, with informative purposes being the most common. While the purpose of the read alouds was to inform, fiction texts were dominant with minimal non-fiction, or discipline-specific texts being used in the content areas. The use of fiction for informative purposes resulted in limited evidence that teacher read aloud was used to develop literary understandings. Teachers reported having limited resources for professional development and limited infrastructure to support effective read aloud. Findings of this study can be used to inform us that teacher read aloud may be a common practice in terms of taking place in most classrooms; however, the time invested, both in frequency and duration, is limited, giving children minimal opportunities to apprentice into a reading community. Findings from this study also provide evidence that traditional practices can continue to be effective, but these practices should be renewed to support better the current and evolving understandings of literacy and literary exposure. Professional development and opportunities to reflect on practice could ameliorate this renewal for in-service and pre-service teachers.
53

Lärarens didaktiska högläsning : Ett redskap in i förståelsen och upplevelsen

Elovsson, Cecilia, Blomgren, Fredrika January 2014 (has links)
Högläsning är en vanligt förekommande aktivitet i dagens klassrum. Forskning visar dock på att lärarens högläsning i många fall behöver effektiviseras. Syftet med arbetet är att undersöka vilka effekter lärarens högläsning av berättande texter har på elevers läsförståelse och läsupplevelse i årskurs 4-6. Vidare är syftet att belysa hur lärarens högläsning kan användas som ett didaktiskt redskap för att utveckla elevers läsförståelse och öka deras läsupplevelse. Fokus i arbetet ligger på berättande texter då forskningen visar på att de är de mest förekommande texttyperna i årskurs 4-6. De frågeställningar arbetet besvarar är följande: Vilka effekter har lärarens högläsning av berättande texter på elevers läsförståelse och läsupplevelse? Hur kan lärarens högläsning av berättande texter didaktiskt utformas? Undersökningsmaterialet består till största del av internationella studier, artiklar och nationella forskningsrapporter, vilka har analyserats och jämförts. Att materialet ska vara riktat mot lärarens högläsning och hur högläsningen kan effektiviseras utgör ett obligatoriskt kriterium. Lärarens högläsning av berättande texter visar sig ha en positiv inverkan på elevers läsförståelse och läsupplevelse. Men avgörande för att högläsningen ska kunna bli effektiv, lärorik och meningsfull är att det finns tid och ett syfte med högläsningen. Om läraren inte uppfyller dessa krav kan högläsningen istället få negativa effekter.
54

Realistic read-out and control for Si:P based quantum computers

Testolin, Matthew J. January 2008 (has links)
This thesis identifies problems with the current operation proposals for Si:P based solid-state quantum computing architectures and outlines realistic alternatives as an effective fix. The focus is qubit read-out and robust two-qubit control of the exchange interaction in the presence of both systematic and environmental errors. We develop a theoretical model of the doubly occupied D- read-out state found in Si:P based nuclear spin architectures. We test our theory by using it to determine the binding energy of the D- state, comparing to known results. Our model can be used in detailed calculations of the adiabatic read-out protocol proposed for these devices. Regarding this protocol, preliminary calculations suggest the small binding energy of the doubly occupied read-out state will result in a state dwell-time less than that required for measurement using a single electron transistor (SET). We propose and analyse an alternative approach to single-spin read-out using optically induced spin to charge transduction, showing that the top gate biases required for qubit selection are significantly less than those demanded by the adiabatic scheme, thereby increasing the D+D- lifetime. Implications for singlet-triplet discrimination for electron spin qubits are also discussed.
55

Impact of the Read Naturally Program on elementary students /

Johnsrud, Brenda Lee Ann. January 2005 (has links)
Thesis (M.S.)--Minot State University, 2005. / Includes bibliographical references (leaves 40-42).
56

Linguistic Features of Instructional Language During Read Aloud Lessons

Bender, Franklin 11 January 2019 (has links)
The purpose of this study was to explore the linguistic architecture of instructional language used during first grade read aloud lessons. The participants were from the CTL Year-3 Read Aloud study. The study’s random assignment created 20 teachers in the treatment group and 19 teachers in the control group. My study investigated the variability of their teacher’s use of instructional language during direct instruction read aloud lessons. Specifically, I analyzed the following linguistic attributes: (a) clausal density, (b) number of different words, (c) words per minute, (d) percentage of maze words, and (e) number of abandoned utterances. Exploratory associations for these variables were compared against the Quality Classroom Instruction protocol (QCI), a measure of teaching effectiveness. The results of my study yielded null effects due study limitations. However, the explored area addressed a blind-spot within the literature and provided preliminary data, insight, and recommendations pertaining to the linguistic attributes of instructional language used by first grade teachers during read aloud lessons.
57

WFS: um sistema de arquivos baseado na política Write- Once Read-Many no espaço do usuário

Lins Falcão, Tiago 31 January 2011 (has links)
Made available in DSpace on 2014-06-12T15:57:32Z (GMT). No. of bitstreams: 2 arquivo3206_1.pdf: 2192848 bytes, checksum: a287d32550b087e7e9d0890e71b7c07b (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / RESUMO O constante crescimento da quantidade de dados armazenados em computadores trouxe a necessidade de assegurar a integridade e a confiabilidade dessas informa¸c oes. Dessa forma, princ´ıpios como os do Write-Once Read-Many (WORM) podem ser aplicados para reduzir o risco associado _ à perda de informações involuntariamente. Este trabalho apresenta um sistema de arquivos WORM, o WFS, implementado a partir da infraestrutura FUSE. Este sistema fornece os recursos fundamentais WORM, por exemplo, não permitindo que os arquivos e diret´orios sejam renomeados ou removidos ou que haja a utilização de comandos de superusuário. O WFS possui o foco em usuários domésticos, que precisam armazenar dados como e-mails, fotos, músicas, sem um alto investimento financeiro. Como principais requisitos do sistema desenvolvido, podemos citar: ser código-livre; atender a usuários sem privilégios de administração; ser instalado e configurado facilmente; apresentar desempenho satisfatório; possibilitar uma forma alternativa de modifica ção e de remoção; permitir o gerenciamento dos dados de forma simples. Por fim, uma avaliação de desempenho foi realizada com o objetivo de reduzir a perda de desempenho em relação ao Ext3. Para tal, técnicas de experimento fatorial 2k foram utilizadas. Ficou constatado que, para a carga de teste utilizada, o WFS introduziu uma perda de desempenho inferior a 12% quando comparado ao Ext3 não-WORM
58

Högläsning i förskolan för barns språkutveckling : Förskollärarens metoder och långsiktiga resultat / Read aloud sessions in preschool for children's language development : preschool teachers' methods and long-term results

Vestlund, Isabelle January 2019 (has links)
Syftet med detta examensarbete är att undersöka vad forskningen säger om högläsning i förskolan. Frågeställningen handlar om vilka metoder förskollärare använder vid högläsning och vilka långsiktiga effekter dessa metoder har på barns språk. Detta arbete har en sociokulturell utgångspunkt och skrivs som en litteraturstudie därmed används innehållsanalys som metod.    Resultatet visar att det finns många effektiva metoder som förskollärare kan använda vid högläsning för att stödja barns språk. Det är framför allt en metod som förespråkas inom forskningen, att föra samtal och dialoger med barnen. Dessa dialoger bör enligt forskarna utgå ifrån barnens livsvärld. Även rollspel framhålls som en effektiv metod för att stötta barnens språkutveckling. Barn lär på olika sätt och därför är det viktigt att lärarna är medvetna om didaktiska val när de planerar undervisningen.
59

Högläsningens betydelse för elevers ordförråd : En litteraturstudie om hur lärare kan använda högläsning för att stötta elevers ordförråd / The Importance of Reading Aloud for Students´ Vocabulary : A literature study on how teachers can use read aloud to support students’ vocabulary

Friberg, Linda, Sjöström, Sara January 2019 (has links)
Syftet med denna litteraturstudie är att beskriva hur lärares högläsning kan stötta yngre skolelevers ordförråd. Undersökningen fokuserar på elever från förskoleklass upp till årskurs tre. Litteraturstudien baseras på 11 vetenskapliga artiklar som har hittats genom digitala och analoga sökningar. Urval och avgränsningar har genomförts.     Resultatet i litteraturstudien visar att lärare bör inkludera facklitterära texter och ordförklaringar i sin högläsning. Det har även visat sig vara gynnsamt att lärare arbetar med repeterad läsning samt att inkludera multimodala verktyg i högläsningen då detta bidrar till att elever utvecklar sitt ordförråd.
60

Diagnosis of Constant Faults in Read-Once Contact Networks over Finite Bases using Decision Trees

Busbait, Monther I. 05 1900 (has links)
We study the depth of decision trees for diagnosis of constant faults in read-once contact networks over finite bases. This includes diagnosis of 0-1 faults, 0 faults and 1 faults. For any finite basis, we prove a linear upper bound on the minimum depth of decision tree for diagnosis of constant faults depending on the number of edges in a contact network over that basis. Also, we obtain asymptotic bounds on the depth of decision trees for diagnosis of each type of constant faults depending on the number of edges in contact networks in the worst case per basis. We study the set of indecomposable contact networks with up to 10 edges and obtain sharp coefficients for the linear upper bound for diagnosis of constant faults in contact networks over bases of these indecomposable contact networks. We use a set of algorithms, including one that we create, to obtain the sharp coefficients.

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