The purpose of the present study was to explore ESL students’ interactions in task-based synchronous computer-mediated communication (SCMC) in Second Life, a virtual environment by which users can interact through representational figures. I investigated Low-Intermediate and High-Intermediate ESL students’ interaction patterns before, during, and after three kinds of tasks, a Jigsaw task, a Decision-making task, and a Discussion task. The findings were that the Low and High-Intermediate ESL students engaged in several forms of interaction during the pre- and post-task periods in Second Life, such as checking their voice chat function, checking members, moving their avatars, and closings. These activities pointed to the nature of Second Life voice chat interaction as preconditions for further conversation, and for closing their conversation. Official task period activities revealed factors for task success, such as a leader, a structured way of approaching a task, no technical problem, and establishing a sense of telepresence (Schroeder, 2002) before the task. Concerning negotiation of meaning, the High-Intermediate students made more negotiation during the Decision-making tasks than the Jigsaw tasks, caused mainly by lexical meanings. The wrong answer team and the incomplete team engaged in more negotiations than the correct answer team and the complete team. However, the Low-Intermediate students in the complete team made more negotiations of meaning than the incomplete team. Both levels of students had fewer negotiations during the Discussion task than in the Jigsaw and Decision-making tasks, and they used comprehension checks, confirmation checks, and clarification requests as strategies for negotiation, overwhelmingly focused on meaning rather than form. The students played with their avatars more often during the Discussion task session than during the Jigsaw or Decision-making tasks, and their use of avatars seemed simply to be for fun, although another way explaining what students were doing is to recognize that they were also exploring the affordances of Second Life. Generally, the Low-Intermediate students had a positive attitude toward their learning experience in Second Life, whereas the High-Intermediate students expressed a more neutral view of their experience in Second Life. / text

Based on the premise that novice EAL learners have limited working memory resources to comprehend academic text, L1 explanatory notes were seen as a possible instrument to use in decreasing the cognitive demands of reading and increase the available working memory resources available for discussions. The hypotheses of this study were largely unsupported but from the data emerged a new hypothesis for second language acquisition; The Formality Hypothesis. This hypothesis posits that the presence or absence of the L1 signals various levels of formality in the learning task. Isolation of the L2 may therefore signal high levels of formality leading to the development of learners’ CALP (Cummins, 1979) whereas incorporation of the L1 into L2 input signals lower levels of formality leading to the development of learners’ BICS (Cummins, 1979).

Based on the premise that novice EAL learners have limited working memory resources to comprehend academic text, L1 explanatory notes were seen as a possible instrument to use in decreasing the cognitive demands of reading and increase the available working memory resources available for discussions. The hypotheses of this study were largely unsupported but from the data emerged a new hypothesis for second language acquisition; The Formality Hypothesis. This hypothesis posits that the presence or absence of the L1 signals various levels of formality in the learning task. Isolation of the L2 may therefore signal high levels of formality leading to the development of learners’ CALP (Cummins, 1979) whereas incorporation of the L1 into L2 input signals lower levels of formality leading to the development of learners’ BICS (Cummins, 1979).

Master of Engineering by Research / Service-level-agreement (SLA) monitoring measures network Quality-of-Service (QoS) parameters to evaluate whether the service performance complies with the SLAs. It is becoming increasingly important for both Internet service providers (ISPs) and their customers. However, the rapid expansion of the Internet makes SLA monitoring a challenging task. As an efficient method to reduce both complexity and overheads for QoS measurements, sampling techniques have been used in SLA monitoring systems. In this thesis, I conduct a comprehensive study of sampling methods for network QoS measurements. I develop an efficient sampling strategy, which makes the measurements less intrusive and more efficient, and I design a network performance monitoring software, which monitors such QoS parameters as packet delay, packet loss and jitter for SLA monitoring and verification. The thesis starts with a discussion on the characteristics of QoS metrics related to the design of the monitoring system and the challenges in monitoring these metrics. Major measurement methodologies for monitoring these metrics are introduced. Existing monitoring systems can be broadly classified into two categories: active and passive measurements. The advantages and disadvantages of both methodologies are discussed and an active measurement methodology is chosen to realise the monitoring system. Secondly, the thesis describes the most common sampling techniques, such as systematic sampling, Poisson sampling and stratified random sampling. Theoretical analysis is performed on the fundamental limits of sampling accuracy. Theoretical analysis is also conducted on the performance of the sampling techniques, which is validated using simulation with real traffic. Both theoretical analysis and simulation results show that the stratified random sampling with optimum allocation achieves the best performance, compared with the other sampling methods. However, stratified sampling with optimum allocation requires extra statistics from the parent traffic traces, which cannot be obtained in real applications. In order to overcome this shortcoming, a novel adaptive stratified sampling strategy is proposed, based on stratified sampling with optimum allocation. A least-mean-square (LMS) linear prediction algorithm is employed to predict the required statistics from the past observations. Simulation results show that the proposed adaptive stratified sampling method closely approaches the performance of the stratified sampling with optimum allocation. Finally, a detailed introduction to the SLA monitoring software design is presented. Measurement results are displayed which calibrate systematic error in the measurements. Measurements between various remote sites have demonstrated impressively good QoS provided by Australian ISPs for premium services.

To master English to such a degree that you can read a wide variety of English texts without having to look certain words up in a dictionary requires a huge vocabulary. Estimates are that you will need to understand 8000 – 9000 word families to reach that goal. The aim of this study was to investigate what opportunities for reaching such a goal there are to be found in the explicit vocabulary instructions found in two textbooks written for Swedish upper-secondary school. Another point of study was how these textbook instructions are related to research in fields relevant to L2 vocabulary acquisition. It was found that there is a good variety in textbook instructions concerning issues such as semantic groups, formulaic sequences and word formation. However, there are big differences between the two textbooks that were studied regarding this. Furthermore, it was found that both textbooks, although having different approaches to teaching vocabulary, rest their reasoning upon research.

In this study called "Effect of fluoranthene and flurochloridone on grow, metabolism and production of pea plants (Pisum sativum L.)" it was study the relationship between this organic pollutants and development of root system, photosynthetic parameters and production ability of pea plants cultivated in Richter nutrient solution. Quantum yield of PS II, specific leaf area (SLA), content of ABA in leaves and production ability was evaluated during the long time cultivation. The most degradation of production parameters was detected in plants influenced by FLU. The same chemical caused the significant differences in anatomy and morphology of root system. Both of used chemical, FLT and FLU, influenced the experimental plants very strongly and their presence caused damage of number of physiological processes.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / ComputaÃÃo em Nuvem ou Cloud Computing à um paradigma promissor de computaÃÃo orientada a serviÃos. O seu maior benefÃcio à a elasticidade, isto Ã, a capacidade do sistema de adicionar e remover recursos automaticamente em tempo de execuÃÃo. Para isso, à essencial projetar e implementar uma tÃcnica efetiva e eficiente que tire proveito da flexibilidade do sistema. Dessa forma, prover elasticidade requer monitorar continuamente (ou prever) a demanda do sistema por recursos, com objetivo de decidir quando adicionÃ-los e removÃ-los. Este trabalho apresenta um mÃtodo de monitoramento nÃo-intrusivo e contÃnuo de SGBDs relacionais em uma infraestrutura de nuvem, visando minimizar a quantidade de mÃquinas virtuais provisionadas para o processamento de consultas, e consequentemente maximizar o uso eficiente do ambiente do provedor. AlÃm disso, ele visa satisfazer um "acordo de nÃvel de serviÃo", em inglÃs service-level agrement (SLA), associado a cada consulta submetida ao sistema. Dessa forma, um objetivo desse trabalho tambÃm à minimizar a penalidade paga pelo provedor para os casos em que ocorre a violaÃÃo do SLA. AlÃm do mÃtodo de monitoramento, este trabalho tambÃm apresenta um mÃtodo de provisionamento de MVs para o processamento da consulta como contribuiÃÃes. Nossa estratÃgia de monitoramento à aplicada a consultas select-range e consultas com agregaÃÃo sobre uma Ãnica tabela. Os experimentos foram realizados na infraestrutura de nuvem da Amazon, confirmando que nossa tÃcnica à elÃstica, permitindo ajustar os recursos alocados no sistema de forma automÃtica e dinÃmica, com base no SLA acordado.

Submitted by Daniella Sodre (daniella.sodre@ufpe.br) on 2015-03-10T13:26:34Z No. of bitstreams: 2 dissertação Cyros da Silva.pdf: 1649531 bytes, checksum: 7f67a5d2cb492b92a5fd69b6fc1ffb74 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-10T13:26:34Z (GMT). No. of bitstreams: 2 dissertação Cyros da Silva.pdf: 1649531 bytes, checksum: 7f67a5d2cb492b92a5fd69b6fc1ffb74 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013-09-12 / A virtualização de servidores tem trazido mudanças no mundo da hospedagem de sites e aplicações web. Na abordagem tradicional, por questões de isolamento cada máquina física fica atrelada a uma aplicação ou a um serviço, o que acarreta em uma subutilização dos recursos computacionais. A virtualização de servidores supera essa limitação proporcionando diversos benefícios como: a redução nos custos operacionais (dado que são necessárias menos máquinas físicas), utilização mais eficiente dos recursos e um menor tempo para disponibilização de servidores. A utilização de acordos de nível de serviço (SLAs) é uma prática comum que ocorre na hospedagem de aplicações web. No entanto, existem desafios no cumprimento de SLAs em ambientes virtualizados. Um deles é que não é trivial converter os objetivos de nível de serviço (SLOs) que usam métricas de nível de aplicação, como tempo de resposta ou transações por segundo, na alocação de recursos de baixo nível, como CPU e memória. Além disso, visto que a carga de trabalho em que os servidores são submetidos varia com o tempo, alocações de recursos estáticas só são suficientes para garantir o nível de serviço se os recursos forem alocados para os picos de demanda, o que leva a subutilização no restante do tempo. Nesta dissertação foi desenvolvida uma solução de monitoramento e controle que ajusta dinamicamente os parâmetros do escalonamento de CPU do ambiente virtualizado de forma a evitar que os acordos de nível de serviço sejam violados. A abordagem utilizada foi derivada de um controlador de referência na literatura. Foram realizados experimentos num ambiente com o hypervisor Xen usando uma aplicação e cargas representativas, e as soluções foram avaliadas. Os resultados obtidos foram compatíveis para os cenários investigados.

Tato práce si klade za cíl seznámit studenty i profesionály z oblasti IT o čem disciplína Service Management (SM) a proces Service Level Management (SLM) je v prostředí korporátní společnosti. Práce obsahuje příklady různých SLM nástrojů a metod, které jsou skutečně používány (například v manažerském nástroji typu Balanced Scorecard). Zvláštní důraz je kladen na překážky, jež mohou nastat a jak je překonat. Tak jako každá zkušenost toto je pouze jeden z přístupů k SLM, ale pokud přispěje k lepšímu osvícení čtenáře, pak splnila svůj cíl. K dosažení těchto záměrů využívám svých dvou a půl letých zkušeností z práce na projektech ve společnosti DHL a ostatních zdrojů popisujících teoretickou rovinu. První část mé diplomové práce poskytuje teoretickou znalost problematiky, druhá část pak převádí tyto znalosti do podnikové praxe.

archives@tulane.edu / The goal of this research was to establish a novel digital manufacturing-based workflow for the fabrication of membrane free organ chip (MFOC) systems. This workflow is based on the implementation of top-down design, starting with CAD design of molds for MFOC components and can be conducted on a benchtop removing the need for cleanroom use. In conducting this research, a commercially available SLA printer was characterized and optimized for manufacturing molds suitable for MFOC fabrication. To achieve this, extensive research was required to determine printer resolution limits and work within the limitations of the resins available for printing. Specifically, the molds need to be flat and smooth in order to produce perfectly horizontal and transparent PDMS devices. Post-processing workflows were engineered to satisfy these MFOC design constraints. After establishing a reliable and reproducible workflow for MFOC fabrication, the focus of the research was reduction to practice, i.e. achieving a design that enables loading MFOC with patterned aqueous solutions with 100% success and a high degree of forgiveness. Key MFOC dimensions were systematically varied in a manner only possible with the rapid prototyping capability of DM in a series of experiments with a standardized injection test and success rate of loading as the primary output. With a robust MFOC design in place, more complex designs for tissue patterning applications were created, and advanced configurations for engineering patterned vascularized stromal tissues were tested and validated. Seqeuntial and simultaneous loading scenerios were imvestigated to better understand cell migration impedence in multi-gel lane devices. / 1 / William Bralower