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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

Manufacturing structurally integrated three dimensional phased array antennas

Pine, Shannon Robert 06 April 2006 (has links)
A phased array antenna differs from a conventional antenna, such as a dish antenna, in that it coherently adds radiation from multiple radiating elements instead of mechanical positioning to direct RF energy. When transmitting and receiving information from a source while in motion, a phased array antenna can continuously adjust its signal to focus on the source. New antenna designs focus on integrating phased array antennas into the structure of the antenna platform, as advanced antenna platforms require the antenna to take up less and less real estate. With further development of phased array antennas, new designs become increasingly complex. The manufacturing techniques to facilitate the integration of complex antenna designs into the structure of an antenna platform must be developed, as traditional manufacturing operations, such as injection molding, machining and bulk deformation processes, are not well suited to create the small details and complex three dimensional lattice designs of the antennas. Innovative solutions need to be developed that allow the manufacture of complex antennas, thereby enabling testing to be performed on actual devices. The results from testing physical models can buttress analytical models and lead to better antenna designs. This work developed and studied suitable methods for manufacturing three-dimensional, structurally-integrated antennas.
52

Describing and analyzing English as a Lingua Franca

Dunlap, Katie J. 15 April 2013 (has links)
Researchers are becoming increasingly interested in responding to the effects of the English language’s viability as a Lingua Franca. English as a Lingua Franca (ELF) is being used predominantly in communication from one non-native speaker to another, and descriptive studies are just beginning to emerge (Dewey 2007; Jenkins, 2000; Seidlhofer, 2004). This report offers a theoretical overview showing ELF’s increasing relevance, and reviews empirical studies that have investigated how ELF is manifesting in the field of language education. These empirical studies are gaining significant traction, specifically in relation to descriptive linguistics, sociolinguistics, and applied linguistics (House, 2003; Mauranen, 2003). In order to investigate a formal description of ELF, recent empirical work is reviewed after two seminal articles were published that helped gain viability into ELF as a distinct research area (i.e. Seidlhofer, 2001; Mauranen, 2003). Such reviews of empirical studies through the use of corpora are not meant to distinguish ELF as a distinct variety of English, but to simply allow for a deep description of how ELF is being used currently. Also discussed are the developments to English language pedagogy and directions for future research as ELF scholars begin to re-conceptualize what is meant by language context and communication in ELF. / text
53

Tillägnande av ordförråd hos sent anlända elever i nationella gymnasiekurser / Vocabulary acquisition and the second language learner

Alf, Kerstin, starck, erik January 2010 (has links)
Abstract It is unclear how L2 students acquire vocabulary – how is it taught – or wheather it can even be taught. In an SSL (Swedish as second language) program for young adults the ambition has been to integrate the L2 students’ into the national high school (gymnasium) courses as quickly as possible, in order to meet the students’ demands for subject education and to challenge them on an appropriate knowledge level. Teachers noticed quite early that the course – integrated L2 students seemed to have a deeper understanding of words and an easier flow in their speech. The study was conducted to map and learn more about the differences in vocabulary with L2 students who were integrated in the national L1 programs in several subjects and L2 students who have chosen to focus, in an isolated group, on SSL only. How does the students’ vocabulary evolve in relation to time? The study is based on the vocabulary knowledge scale as the methodological tool and Stephen Krashen’s monitor model as the theoretical practice, and in particular the input hypothesis and the hypothesis of acquisition and learning in combination with Pauline Gibbons’s methodologies in scaffolding. In the study the test results of eight SSL students are compared; four of the students have chosen to integrate with the L1 classes and four of them have chosen not to integrate with the L1 students. We will show that students that participate in national “high school” courses on the same premises as the L1 students will, through exposure to vocabulary in text books, lectures and post scaffolding, learn their vocabulary at a faster and higher rate than students who focus on the structural functions and, often non-contextual, vocabulary training alone.
54

IT-Outsourcing for four organizations

Derventzas, Konstantinos January 2010 (has links)
Introduction IT-Outsourcing is a concept that describes the supply of part or all of Information Technology (IT) services by an external supplier company, known as IT-vendor, to a client company. The ‘IS-Improvement’ is one of the three strategic views of IT-Outsourcing for clients and involves advantages like focusing on core business, cost reductions and increase of IT-resources efficiency.   Objectives The purpose of this project is to discover, describe and analyze the most critical aspects in implementing IT-Outsourcing and the critical aspects of the ‘IS Improvement’ view of IT-Outsourcing for clients, to further let IT-vendors know how they can improve on delivering their services to their customers.   Research Question “Which are the most critical factors in implementing IT-Outsourcing and which are the critical aspects of the IS-improvement view of IT-Outsourcing for four organizations as clients?”   Method This project follows an exploratory research method. It is mainly an action research but there is also an element of a realist research. The subject of IT-Outsourcing was chosen because it is part of IT-Management. The analysis is based on primary data collected from four organizations in the European Union (EU) that were chosen because they use IT intensively in their activities. Access to these organizations was because of convenience since it was enabled by personal contacts. Two organizations were in the shipping business, the third organization was an electronic-devices factory, and the fourth was a university. The data collection was based on three face-to-face interviews with the IT-Managers of the organizations, and one response was collected by electronic means since the fourth respondent (also IT-Manager) completed and sent the questionnaire by e-mail. The interviews were based on a semi-structured questionnaire, that in turn was formed based on the content of the critical literature review. The critical literature review was formed from books and articles found at Mälardalens Högskola’s library and databases, and interlibrary loans. The data were inserted in a table for content analysis that helped count the frequencies of the various factors of IT-Outsourcing. The results were drawn based on qualitative analysis and they were tested against dialectical critique.   Conclusions The most critical factors in implementing IT-outsourcing for these four organizations are: Hardware maintenance is the most critical area to be outsourced. Low costs of services, supplier’s stability and reputation are the most critical factors in selecting an IT-vendor. Supplier’s understanding of client’s objectives is the most critical factor for a successful relationship between clients and IT-vendors. Precise definition of costs is the most critical factor to be included in an IT-Outsourcing contract, and selective/partial IT-Outsourcing is the IT-sourcing solution preferred by these organizations. The ‘IS-Improvement’ view of IT-Outsourcing for these four organizations is not valid, but the respondents’ words indicate ways that IT-Outsourcing can be improved to achieve increased IT-resources efficiency.
55

Constructions in child second language acquisition: exploring the role of first language and usage

Zdorenko, Tatiana Unknown Date
No description available.
56

English language attitudes and motivation among adult migrants in Australia

Ratcheva, Silvia January 2007 (has links)
Research Doctorate - Doctor of Philosophy (PhD) / The present investigation is a project in applied linguistics which looks at second language acquisition (SLA) from a social psychological perspective. The study is cross-sectional correlational by design and draws on two social psychological models of SLA, namely: Gardner's (1985) socio-educational model and Schumann's (1978) acculturation model of SLA. The structured interview and survey methods were used to elicit the attitudes toward the speakers of Australian English and motivation for learning English among first generation non-English speaking adult migrants who were permanent settlers in, or citizens of, Australia. The Australian Second Language Proficiency Ratings (ASLPR) scale was used as a global and unobtrusive measure of English language proficiency. The study situates the socio-educational and acculturation models within recent developments of attitude, acculturation, motivation, and SLA theory; explores the differences in attitudes and motivation as a function of respondents' ethnic background and length of residence; and examines the relationship among the various acculturation, motivation and English language proficiency measures.The recurring themes are those of conceptual complexity, of integrativeness which is usually understood in SLA as the learners' social integration and psychological identification with the speakers of the target language, and the impossibility to separate the social from the individual level of analysis in SLA research. The results help to understand the evaluations and stereotype that migrants hold of Anglo-Australians and the values that underlie them. The results also lend support to the proposition (e.g. Dornyei, 2005) that an alternative interpretation of integrativeness in SLA is possible. The findings could be informative to those involved in policy making and in delivering education to migrants.
57

Contrôle des applications fondé sur la qualité de service pour les plate-formes logicielles dématérialisées (Cloud) / Control of applications based on quality of service in Cloud software platforms

Li, Ge 21 July 2015 (has links)
Le « Cloud computing » est un nouveau modèle de systèmes de calcul. L’infrastructure, les applications et les données sont déplacées de machines localisées sur des systèmes dématérialisés accédés sous forme de service via Internet. Le modèle « coût à l’utilisation » permet des économies de coût en modifiant la configuration à l’exécution (élasticité). L’objectif de cette thèse est de contribuer à la gestion de la Qualité de Service (QdS) des applications s’exécutant dans le Cloud. Les services Cloud prétendent fournir une flexibilité importante dans l’attribution des ressources de calcul tenant compte des variations perçues, telles qu’une fluctuation de la charge. Les capacités de variation doivent être précisément exprimées dans un contrat (le Service Level Agreement, SLA) lorsque l’application est hébergée par un fournisseur de Plateform as a Service (PaaS). Dans cette thèse, nous proposons et nous décrivons formellement le langage de description de SLA PSLA. PSLA est fondé sur WS-Agreement qui est lui-même un langage extensible de description de SLA. Des négociations préalables à la signature du SLA sont indispensables, pendant lesquelles le fournisseur de PaaS doit évaluer la faisabilité des termes du contrat. Cette évaluation, par exemple le temps de réponse, le débit maximal de requêtes servies, etc, est fondée sur une analyse du comportement de l’application déployée dans l’infrastructure cloud. Une analyse du comportement de l’application est donc nécessaire et habituellement assurée par des tests (benchmarks). Ces tests sont relativement coûteux et une étude précise de faisabilité demande en général de nombreux tests. Dans cette thèse, nous proposons une méthode d’étude de faisabilité concernant les critères de performance, à partir d’une proposition de SLA exprimée en PSLA. Cette méthode est un compromis entre la précision d’une étude exhaustive de faisabilité et les coûts de tests. Les résultats de cette étude constituent le modèle initial de la correspondance charge entrante-allocation de ressources utilisée à l’exécution. Le contrôle à l’exécution (runtime control) d’une application gère l’allocation de ressources en fonction des besoins, s’appuyant en particulier sur les capacités de passage à l’échelle (scalability) des infrastructures de cloud. Nous proposons RCSREPRO (Runtime Control method based on Schedule, REactive and PROactive methods), une méthode de contrôle à l’exécution fondée sur la planification et des contrôles réactifs et prédictifs. Les besoins d’adaptation à l’exécution sont essentiellement dus à une variation de la charge soumise à l’application, variations difficiles à estimer avant exécution et seulement grossièrement décrites dans le SLA. Il est donc nécessaire de reporter à l’exécution les décisions d’adaptation et d’y évaluer les possibles variations de charge. Comme les actions de modification des ressources attribuées peuvent prendre plusieurs minutes, RCSREPRO réalise un contrôle prédictif fondée sur l’analyse de charge et la correspondance indicateurs de performance-ressources attribuées, initialement définie via des tests. Cette correspondance est améliorée en permanence à l’exécution. En résumé, les contributions de cette thèse sont la proposition de langage PSLA pour décrire les SLA ; une proposition de méthode pour l’étude de faisabilité d’un SLA ; une proposition de méthode (RCSREPRO) de contrôle à l’exécution de l’application pour garantir le SLA. Les travaux de cette thèse s’inscrivent dans le contexte du projet FSN OpenCloudware (www.opencloudware.org) et ont été financés en partie par celui-ci. / Cloud computing is a new computing model. Infrastructure, application and data are moved from local machines to internet and provided as services. Cloud users, such as application owners, can greatly save budgets from the elasticity feature, which refers to the “pay as you go” and on-demand characteristics, of cloud service. The goal of this thesis is to manage the Quality of Service (QoS) for applications running in cloud environments Cloud services provide application owners with great flexibility to assign “suitable” amount of resources according to the changing needs, for example caused by fluctuating request rate. “Suitable” or not needs to be clearly documented in Service Level Agreements (SLA) if this resource demanding task is hosted in a third party, such as a Platform as a Service (PaaS) provider. In this thesis, we propose and formally describe PSLA, which is a SLA description language for PaaS. PSLA is based on WS-Agreement, which is extendable and widely accepted as a SLA description language. Before signing the SLA contract, negotiations are unavoidable. During negotiations, the PaaS provider needs to evaluate if the SLA drafts are feasible or not. These evaluations are based on the analysis of the behavior of the application deployed in the cloud infrastructure, for instance throughput of served requests, response time, etc. Therefore, application dependent analysis, such as benchmark, is needed. Benchmarks are relatively costly and precise feasibility study usually imply large amount of benchmarks. In this thesis, we propose a benchmark based SLA feasibility study method to evaluate whether or not a SLA expressed in PSLA, including QoS targets, resource constraints, cost constraints and workload constraints can be achieved. This method makes tradeoff between the accuracy of a SLA feasibility study and benchmark costs. The intermediate of this benchmark based feasibility study process will be used as the workload-resource mapping model of our runtime control method. When application is running in a cloud infrastructure, the scalability feature of cloud infrastructures allows us to allocate and release resources according to changing needs. These resource provisioning activities are named runtime control. We propose the Runtime Control method based onSchedule, REactive and PROactive methods (RCSREPRO). Changing needs are mainly caused by the fluctuating workload for majority of the applications running in the cloud. The detailed workload information, for example the request arrival rates at scheduled points in time, is difficult to be known before running the application. Moreover, workload information listed in PSLA is too rough to give a fitted resource provisioning schedule before runtime. Therefore, runtime control decisions are needed to be performed in real time. Since resource provisioning actions usually require several minutes, RCSREPRO performs a proactive runtime control which means that it predicts future needs and assign resources in advance to have them ready when they are needed. Hence, prediction of the workload and workload-resource mapping are two problems involved in proactive runtime control. The workload-resource mapping model, which is initially derived from benchmarks in SLA feasibility study is continuously improved in a feedback way at runtime, increasing the accuracy of the control.To sum up, we contribute with three aspects to the QoS management of application running in the cloud: creation of PSLA, a PaaS level SLA description language; proposal of a benchmark based SLA feasibility study method; proposal of a runtime control method, RCSREPRO, to ensure the SLA when the application is running. The work described in this thesis is motivated and funded by the FSN OpenCloudware project (www.opencloudware.org).
58

THE EFFECT OF L1 TRANSLATION VS. L2 DEFINITION ON THE IMMEDIATE RECALL OF VOCABULARY WORDS

Al Hashim, Abdulrahman Saad 01 December 2015 (has links)
Throughout the history of language teaching and its pedagogy, many researchers have turned a blind eye to the pedagogical role of the first language (L1) in the second language (L2) classroom. However, the pendulum has recently swung the other way to indicate possible and effective integration of the (L1) in (L2) classrooms. This study sets out to explore the effect of the L1 and L2 on the recall of ESL vocabulary among low-advanced Saudi learners of English in the U.S. For the purpose of the study, 30 Saudi ESL students were recruited and divided into two groups (L1 translation group and L2 definition group). The L1 translation group received a list of English words translated into Arabic whereas the L2 definition group were given the same list of English words but with English definitions. Participants in both groups were asked to study and memorize the target words along with the meaning of each word. Afterwards, an immediate fill-in-the-blank post-test was given to examine whether L1 translation helps participants recall the given L2 vocabulary. Prior to the post-test, participants were given a questionnaire to indicate the most frequently used strategy when learning L2 vocabulary. After the data were analyzed quantitatively employing an independent t-test, the resultant findings showed that L1 translation indeed promotes the immediate recall of L2 vocabulary among Saudi ESL learners. The data elicited from the questionnaire also provided enough evidence that Saudi ESL learners frequently use Arabic more than other strategies to access and understand English. This study showed that L1 translation has a great positive effect on the learning of L2 vocabulary among low-advanced Saudi ESL learners.
59

PRONUNCIATION PROBLEMS IN THE PRODUCTION OF THE VOICED LABIODENTAL FRICATIVE /v/ BY SAUDI SPEAKERS OF ENGLISH

Alotaibi, Abdullah Nijr 01 May 2013 (has links)
The present study aims to investigate the production of the voiced labiodental fricative /v/ of Saudi Arabian speakers of English in view of linguistic and extra-linguistic factors. The linguistic aspect focuses on the role of the position of the sound in words, initial and final, and the distribution of errors per word in view of more and less familiar words. The extra-linguistic factors include participants' lengths of stay in the US and their ages and the potential influence these may have on the accuracy of pronouncing the target sound /v/. The total number of the subjects is 20 (10 male and 10 female), and their ages range between 20 and 35, with Mean age 27. Data is elicited through participants' reading of a word list with the target sound in initial and final position. The data coding is performed through spectrographic analysis and rater judgments. The analysis employs descriptive statistics, a dependent t-test used to compare production errors between initial and final position, and correlation analyses through which subjects' length of stay in the US and age are correlated with their total number of errors in both word positions. The findings show that word-final position is more difficult in pronouncing the phoneme /v/ than word-initial position. In addition, when the voiced labiodental fricative /v/ is mispronounced, it is substituted with the voiceless labiodental fricative /f/. Also, the correlation analysis shows that the longer the subjects have stayed in the USA, the more accurate their pronunciation of the target sound is (and vice versa). A significant correlation is also found between age and accuracy of pronunciation, as the younger subjects have more accurate pronunciation. The results of this study provide empirical evidence in support of several language acquisition theories, such as Contrastive Analysis Hypothesis (Lado, 1957), Markedness Differential Hypothesis (Eckman, 1977) and Language Transfer Theory (Gass & Selinker, 1994), all of which claim the influence of learners' first language on their second language. In the context of this study, the substitution of the voiced labiodental fricative /v/ with its voiceless counterpart /f/ can be attributed to the fact that /f/ is the only labiodental fricative phoneme in the Arabic language.
60

Effects of Explicit and Implicit Focus on Form Instructional Methods on the Acquisition of Spanish L2 Future of Probability

Goundareva, Irina January 2016 (has links)
This thesis investigated possible effects of explicit and implicit focus on form (FonF) instruction on the acquisition of Spanish future of probability (SFP) by Anglophone and Francophone students at a Canadian bilingual university. We also analyzed a possible L1 transfer from French to L2 Spanish in the acquisition of SFP, due to the typological similarity of this linguistic feature in the two languages. Twenty seven B1/B2 Spanish level students including L1 English and L1 French learners of L2 Spanish were divided into three groups according to the instruction type: explicit focus on form instruction group, implicit focus on form instruction group and control group, which received no additional instruction. All the participants were tested before the lesson (pretest), immediately after (posttest) and four weeks later (delayed posttest). The battery of tests included Untimed Grammaticality Judgment (UGJT), Written Production (WPT) and Oral Production (OPT) tasks. They aimed to test our four hypotheses which focused on both short-term and long-term effects of the two types of instruction on grammaticality judgment, written and oral production of SFP, respectively. The results demonstrated a positive effect of explicit and implicit FonF instruction on grammaticality judgment, oral and written production of SFP compared to the control group. In particular, both instructional groups distinguished grammatical and ungrammatical uses of SFP with state and activity verbs immediately after the treatment. After four weeks, both groups retained the acquired knowledge equally well. In the implicit FonF group we found an advantage of the L1 French over the L1 English students, possibly due to the similarity of the future tense morphology in Spanish and French, as well as the fact that French uses future morphology for present time probability, although in very limited contexts (a subset of state verbs). The results of the WPT suggest an advantage of the explicit FonF group in both immediate and long-term results and showed no difference between the L1s in either of the instructional groups. We also noticed an overgeneralization of the use of SFP with telic verbs in both instructional groups after the treatment, which is considered ungrammatical. Therefore, our participants did not distinguish the written use of telic and atelic verbs in epistemic conditions after the two types of treatment provided. The OPT results demonstrated that similarly to the previous two tasks both experimental groups performed better than the Control group. However, there was no significant difference between the two instructional groups. L1 had no significant effect on the oral production of SFP either. Similarly to the WPT, we found an overgeneralization of the use of SFP in telic verb conditions. Overall, Anglophone and Francophone students appear to have similar opportunities for successful acquisition of SFP and both explicit and implicit FonF instruction, activities and feedback may lead to positive results in the acquisition of SFP. To conclude this thesis, we discuss some challenges of this study and possible directions of future research.

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