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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.
61

Effects of Adaptive Reflection Teaching Strategies on Learners¡¦ Reflection Levels in a Web-based Learning Environment

Liu, Chia-chi 10 July 2009 (has links)
Since personal computers and broadband Internet connections have become more and more prevalent, the application of e-Learning using the Internet is regarded as an important issue. In the literature, reflection plays an important role on improving learning performance. Hence, the issue on how to promote learners¡¦ reflection levels in a web-based learning environment becomes an essential research topic. The purposes of this research were to explore whether there are fits between reflection teaching strategies and thinking styles for better promoting learners¡¦ reflection levels. Further, learners¡¦ satisfactions on reflection learning were also discussed. A total of 223 graduate and undergraduate students, voluntarily participated to use the developed reflection learning system in this research. Twenty four learning situations are presented in the experiment according to the differences of reflection teaching strategies (constructive, guiding, and inductive) and thinking styles (legislative, executive, and judicial). And these learning situations are simplistically classified as fit or non-fit group. Learners were randomly assigned to either fit or non-fit group, and their reflection content was evaluated by two experts who have been well-trained. The results showed that there are fits between reflection teaching strategies and thinking styles for better improving learners¡¦ reflection levels. On the other hand, there is no significant difference on learners¡¦ satisfactions of reflection learning, but learners¡¦ average satisfactions on this kind of reflection learning is positive. Furthermore, this research also finds out that learners with at least one thinking style ranking on top of 25% adopting inductive reflection teaching strategy have higher satisfactions on reflection learning than learners adopting guiding reflection teaching strategy.
62

Video reflection in teacher professional development

Bell, Randy Clinton 25 November 2013 (has links)
The goal of this report is to synthesize my current understanding of teacher reflective practice as addressed in academic literature and to specifically examine the potentials and limitations of video recording in the reflective process of teachers. I trace my experience and growth in reflective practice as a bilingual elementary school teacher and consider how teachers as researchers/participants in reflective practice cohorts can contribute to the professionalism of teaching. As a result of my findings I make recommendations toward appropriate professional develop using video reflection as a key component in the development of novice teachers via the mentor/mentee framework. This report contributes to the knowledge base regarding reflective practice and to the growing literature on video recording in the reflective process of teachers. It also provides insights into the potential for action-based research by practicing teachers. Implications and recommendations for teachers and researchers are included. / text
63

Reflektionssamtalets möjligheter och begränsningar : En undersökning om det stöttande reflektionssamtalet som skrivutvecklande metod inom Sfi-undervisning

Lind, Maja January 2010 (has links)
Writing is a critical element for many of the second language learners that I’ve encountered in my work as a Swedish teacher. Therefore, on the basis of Jerome Bruners theories of reflec-tion and learning, was the purpose with this study to examine the scaffolded structured reflec-tion conversation as a method for writing development. Bruner says that the knowledge be-comes deeper when we consciously reflect over it (Arfwedson 1992:110 f). I have used a qualitative method where I let five students write a text in Swedish on the subject "application for internship". After that I held a conversation with each of the pupils. By asking them questions I wanted them to reflect on their writing process, and the language and content in their written texts. After this I let the students revise the texts, with the invita-tion to use the thoughts from the conversation. By this I wanted to examine to which extent the five reflection conversations led to reflec-tion on the students' own writing, as well as on language and content in the texts. I also wanted to examine how the students changed their texts after the conversations and which factors can be interpreted as being significant for the outcome of the conversations. The study has shown that the outcome of the scaffolded structured reflection conversa-tions is very much dependent on the students' respective inputs and focus of the talks. The results indicate that a person who enters the conversation with a focus on developing his/her writing in general is generally more inclined to reflect than a student who enters with a strong focus on the individual task. These results also finds support in earlier theories of reflection. In accordance with previous research, this study also demonstrated that it is essential that the reflection is based on the individuals’ circumstances and experiences. I had before the conversations constructed a manual with questions, which I used in all conversations. The results show that only those students who during the conversation were within what Vygotskij calls the zone of proximal development, through my questions got the scaffolding that they needed to reflect.
64

Šviesos atspindys nuo homogeninės anizotropinės aplinkos / Light reflection of homogeneous anizotropic Media

Jurevičiūtė, Asta 16 August 2007 (has links)
Šiame darbe nagrinėjamas šviesos atspindžio parametrų priklausomybė nuo SbSI kristalo įvairių kristalografinių plokštumų atžvilgiu.Tai darboma sukurtos skaičiavimo programo spagalba. / On purpose about structure of the light, you must to make measurement of light reflections parameters. Following are outputting of equation of the Fresnel. Parameters of light reflection describe . In this work we finding following parameters with the help of the program “Mathematica”. And we finding the contingent on light incidence , rotate angle , anisotropy coefficient a.
65

Deconvolution of seismic data using extremal skew and kurtosis

Vafidis, Antonios. January 1984 (has links)
No description available.
66

QUANTIFICATION OF SURFACE DEFECTS USING PRIMARY HIGHLIGHT IN DIFFUSE ANGLE GRAY SCALE IMAGES

Ganapathiraman, Subburengan 01 January 2005 (has links)
The thesis presented is an effort to gather all possible information of one particular type of common paint defect the seed defect, from gray scale images of highly specular painted surface. The proposed approach in the thesis utilizes a white light source to illuminate the surface and utilizes a camera to capture its gray scale image at different diffused angles. While attempting to explain the physics of highlight formation in terms of location on the surface of a seed defect, the thesis also extends to utilize this information from gray scale images to accurately predict the parameters of seed defects including the height, size and position in real time. Since the primary highlight in a gray scale image is more defined, contrary to the past researches on diffuse angle images that use both primary / seed highlight and mirror highlight to estimate height of the seed, this thesis formulates a theory of highlight translation and estimates the height of seed based on primary / seed highlight. The other common type of surface defect - crater defect, is also addressed in the thesis.
67

Migration by the diffraction stack method /

Mohanty, Priya Ranjan. January 1984 (has links)
Thesis (M.Sc.) -- Memorial University of Newfoundland. / Typescript. Bibliography : leaves 108-112. Also available online.
68

Cálculo dos coeficientes de reflexão e transmissão em meios anisotrópicos / Calculation of the reflection and transmission coefficients in anisotropic media

Cypriano, Luís Fernando Katsuda Ito 16 August 2018 (has links)
Orientador: Rodrigo de Souza Portugal / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-16T15:44:25Z (GMT). No. of bitstreams: 1 Cypriano_LuisFernandoKatsudaIto_M.pdf: 3729581 bytes, checksum: 3c24bb11c96e5ce9e394fb618e43ea9c (MD5) Previous issue date: 2010 / Resumo: A maioria dos métodos de imageamento de subsuperfície aplicados em projetos de Exploração e Produção (E&P) de hidrocarbonetos assume o meio elástico isotrópico (ISO). Os meios isotrópicos, em contrapartida aos modelos anisotrópicos, são aqueles cujas velocidades das ondas sísmicas não dependem da direção de propagação. Entretanto, muitas rochas obtidas de testemunhos apresentam anisotropia. Logo, é natural que estudos dos meios anisotrópicos sejam feitos com o intuito de aumentar a precisão do imageamento sísmico. As anisotropias são classificadas de acordo com as simetrias apresentadas. As simetrias mais comuns em exploração de hidrocarbonetos são as simetrias transversalmente isotrópicas (TI) e ortorrômbicas (ORT). Quando uma onda impinge uma interface são geradas ondas refletidas e transmitidas. A razão entre as amplitudes dos vetores de deslocamento da onda incidente em relação às ondas geradas são os coeficientes de reflexão/ transmissão (R/T) de deslocamento. Os coeficientes R/T podem ser expressos explicitamente por fórmulas apenas em casos de alta simetria, por exemplo, isotrópica. Caso contrário os coeficientes R/T devem ser obtidos de um sistema de equações algébricas lineares obtidas das condições de contorno na interface. Neste trabalho desenvolvemos um código para calcular os coeficientes de reflexão e transmissão (R/T) para interfaces entre meios anisotrópicos. Dois critérios para a distinção das ondas geradas na interface são adotados em adição ao critério convencional da literatura. As simetrias utilizadas para os testes sintéticos foram as simetrias ISO, TI e ORT. O testes exemplificam algumas características básicas dos coeficientes R/T, como equivalência entre interfaces e simetrias inclinadas e a reciprocidade dos coeficientes normalizados pela energia / Abstract: The great majority of the methods for imaging subsurface invested in hydrocarbons Exploration and Production (E&P) assumes isotropic elastic medium (ISO). The isotropic models are those which velocities of seismic waves do not depend on the direction of propagation. However many core rocks exhibit anisotropy. Thus, the assumption of anisotropic media is natural in order to increase the accuracy of seismic imaging. The anisotropies are classified according to their symmetries. The most common symmetries in hydrocarbon E&P are the transversely isotropic (TI) and orthorhombic (ORT) symmetries. When a seismic wave impinges at an interface between two media, it generates reflected and transmitted waves. The ratio between the amplitudes of displacement vectors of the incident and the generated waves are the displacement reflection/transmission (R/T) coefficients. The R/T coefficients can be expressed by explicit formulas in cases of higher symmetries, e.g. isotropy. Otherwise they are obtained numerically from a system of inhomogeneous linear algebraic equations derived from the boundary conditions in the interface. We develop a code to evaluate the R/T coefficients interfaces between two anisotropic media. We adopt two criteria in addition to the conventional one for distinguishing the generated waves. The symmetries used for the synthetic tests were symmetries ISO, TI and ORT. The tests illustrate some basic characteristics of the R/T coefficients, as equivalence between tilted symmetries and interfaces, and the reciprocal of the energy normalized R/T coefficients / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo
69

MODE LOCKED RESONANCE VIA INTERNAL AND EXTERNAL REFLECTIONS

Elrifaei, Eman 01 May 2020 (has links)
The goal of this research was to study the polarization effect on the achievability of mode locked laser signal in accordance to polarization dependency. Polarization characterization was studied in prior to mode locking to determine semiconductor optical amplifiers (SOA) polarization dependency. It was found that per SOA manufacturer a variation of dependency was recognized. Two setups were suggested based on dissipative soliton resonance (DSR) schemes, the external DSR with regenerative feedback and the total internal reflection (TIR) DSR. The laser operated at 1530nm for multiple SOA manufacturers and was capable of generating ultrashort pulses with different durations as listed in Table (3.2.3) and Table (3.3.2). For the external mode-lock, the maximum achieved average output power of 3.40mW corresponding to ~77.15fJ of output pulse energy through continuous pumping by gain modulation of an SOA used as the active medium. While the TIR mode-lock the maximum achieved average output power for mode-locked signal of 5.25mW corresponding to ~23.73fJ of output pulse energy.It was concluded that the output pulse of the external DSR setup showed polarization dependency for two SOAs A and C and provided mode locked signals with pulse width ranging between 1200ps and 1000ps with repetition rate approximately of 35MHz and 101MHz respectively. The TIR DSR had a variation in results also to be polarization related. While SOA D did not provide mode-locked signal output. The least polarization dependent SOAs E and X did not provide distinctive stable mode-locked signal. While increased sensitivity towards polarization however resulted in stronger mode locked signal for SOAs A and C with FWHM between 200ps and 350ps and a repetition rate of approximately 20MHz. For future work, it is recommended to adjust the setup length in addition to fine tuning polarizer and filters to improve pulse stability and eliminate the noise effect.
70

Mathematics teachers' reflection in the context of lesson study and the development of their knowledge for teaching

Reynolds, Marie Susanna Johanna January 2016 (has links)
Questions have been raised about what constitutes effective continuous professional development. Short-term training initiatives for in-service teachers have had limited success as agents of change. Lesson Study, an approach initiated by the Japanese, could address this shortcoming. Lesson Study is a bottom-up approach which emphasises teacher collaboration and where the teacher's subject knowledge and teaching practice are enhanced through individual and group reflection. The purpose of this study is to establish the content of the teachers' reflection in the context of a 'Lesson Study' and to analyse this content against the framework of the Knowledge Quartet. A practical action research approach was adopted for this study. The participants were five mathematics teachers who teach in two non-urban secondary schools. Data in the form of individual reflection notes, video material of the group reflection sessions and my field notes were collected during three Lesson Study cycles conducted over a period of five weeks. Most learners were not from English-speaking backgrounds, but were taught in English. Twelve sub-categories emerged from the teachers' reflection, and these sub-categories were grouped into the four following categories: Teacher focus; Learner focus; Lesson design and Resources. Levels of reflection were deepest in cycle two, a finding in keeping with other similar studies. All dimensions of the Knowledge Quartet were included in the teachers' reflections. However, the focus of experienced teachers differed from that of inexperienced teachers. Action research is based on the assumption that the answers to the research questions posed in a specific study are unique to that study. Since the group dynamics and the relationships within the group are fundamental to action research, any outcomes apply only to a specific group in a specific context and cannot be generalised; this rule applies to Lesson Study. However, I trust that the findings of this study will contribute towards the body of knowledge concerning the use of Lesson Study as a professional development programme which enables teachers to become reflective practitioners and assists them in growing their knowledge for teaching, individually and collectively. Future research could investigate the suitability of Lesson Study for in-service teacher development through all phases of schooling. / Dissertation (MEd)--University of Pretoria, 2016. / Science, Mathematics and Technology Education / MEd / Unrestricted

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