<p>Циљ ове докторске дисертације је да<br />се упоредно анализира колаборативно и<br />самостално писмено изражавање у<br />основношколској настави енглеског језика.<br />Вештина писменог изражавања сматра се<br />комплексном когнитивном језичком<br />вештином, а истовремено игра веома битну<br />улогу у глобалној заједници, тако да је<br />неопходно да се више пажње посвети<br />подучавању писања. Годинама се писање<br />подучавало као производ, а не као процес.<br />Наиме, наставници су наглашавали важност<br />граматике и правописа, а недовољно пажње<br />се посвећивало садржају написаног и<br />организацији идеја. Да би се унапредило<br />писмено изражавање ученика они морају<br />више да се укључе у процес учења.<br />Интеракција се истиче као кључни део<br />учења и тако долази до све чешће<br />колаборације на часовима. У активностима<br />које се баве колаборативним писањем<br />процес сарадње подједнако је битан као и<br />процес писања.<br />Сарадња међу вршњацима и<br />потпомогнуто учење постали су саставни<br />део наставе енглеског језика, али је циљ овог<br />рада био да се провери њихова ефикасност у<br />завршним разредима основне школе.<br />Спроведено је истраживање у току 2014.<br />године са ученицима осмих разреда основне<br />школе. У току истраживања ученици су прво<br />самостално писали саставе, а потом су<br />радили писмене активности у групама. Кроз<br />анализу грешака тих састава дошло се до<br />закључка да ученици у групама, кроз<br />колаборацију, праве мање грешака и пишу<br />кохерентније саставе.<br />У другом делу истраживања ученици<br />су кроз анкете показали своје ставове према<br />оваквим активностима. Претпоставља се да<br />колаборативне активности повећавају<br />мотивацију, ентузијазам и самопоуздање<br />ученика. Како би се употпунило<br />истраживање о ставовима ученика, поред<br />анкетирања, у истраживачки процес била је<br />укључена још и техника групног<br />интервјуисања. На основу добијених<br />резултата може се закључити да нешто више<br />ученика воли колаборативне активности<br />него што их не воли, али је велики број<br />ученика несигуран о својим ставовима. Да<br />би се унапредили ефекти колаборативног<br />учења неопходно је подучити ученике како<br />да ефикасније раде у групи.<br />Наставници играју велику улогу у<br />процесу учења код ученика и умногоме<br />зависи од њих да ли ће ученици процес<br />писања прихватити као забаван или напоран<br />садржај часа. У последњем делу<br />истраживања проверени су и ставови<br />наставника према колаборативном и<br />самосталном писању и може се тврдити да<br />већина наставника има позитиван став према<br />овим активностима.</p> / <p>Cilj ove doktorske disertacije je da<br />se uporedno analizira kolaborativno i<br />samostalno pismeno izražavanje u<br />osnovnoškolskoj nastavi engleskog jezika.<br />Veština pismenog izražavanja smatra se<br />kompleksnom kognitivnom jezičkom<br />veštinom, a istovremeno igra veoma bitnu<br />ulogu u globalnoj zajednici, tako da je<br />neophodno da se više pažnje posveti<br />podučavanju pisanja. Godinama se pisanje<br />podučavalo kao proizvod, a ne kao proces.<br />Naime, nastavnici su naglašavali važnost<br />gramatike i pravopisa, a nedovoljno pažnje<br />se posvećivalo sadržaju napisanog i<br />organizaciji ideja. Da bi se unapredilo<br />pismeno izražavanje učenika oni moraju<br />više da se uključe u proces učenja.<br />Interakcija se ističe kao ključni deo<br />učenja i tako dolazi do sve češće<br />kolaboracije na časovima. U aktivnostima<br />koje se bave kolaborativnim pisanjem<br />proces saradnje podjednako je bitan kao i<br />proces pisanja.<br />Saradnja među vršnjacima i<br />potpomognuto učenje postali su sastavni<br />deo nastave engleskog jezika, ali je cilj ovog<br />rada bio da se proveri njihova efikasnost u<br />završnim razredima osnovne škole.<br />Sprovedeno je istraživanje u toku 2014.<br />godine sa učenicima osmih razreda osnovne<br />škole. U toku istraživanja učenici su prvo<br />samostalno pisali sastave, a potom su<br />radili pismene aktivnosti u grupama. Kroz<br />analizu grešaka tih sastava došlo se do<br />zaključka da učenici u grupama, kroz<br />kolaboraciju, prave manje grešaka i pišu<br />koherentnije sastave.<br />U drugom delu istraživanja učenici<br />su kroz ankete pokazali svoje stavove prema<br />ovakvim aktivnostima. Pretpostavlja se da<br />kolaborativne aktivnosti povećavaju<br />motivaciju, entuzijazam i samopouzdanje<br />učenika. Kako bi se upotpunilo<br />istraživanje o stavovima učenika, pored<br />anketiranja, u istraživački proces bila je<br />uključena još i tehnika grupnog<br />intervjuisanja. Na osnovu dobijenih<br />rezultata može se zaključiti da nešto više<br />učenika voli kolaborativne aktivnosti<br />nego što ih ne voli, ali je veliki broj<br />učenika nesiguran o svojim stavovima. Da<br />bi se unapredili efekti kolaborativnog<br />učenja neophodno je podučiti učenike kako<br />da efikasnije rade u grupi.<br />Nastavnici igraju veliku ulogu u<br />procesu učenja kod učenika i umnogome<br />zavisi od njih da li će učenici proces<br />pisanja prihvatiti kao zabavan ili naporan<br />sadržaj časa. U poslednjem delu<br />istraživanja provereni su i stavovi<br />nastavnika prema kolaborativnom i<br />samostalnom pisanju i može se tvrditi da<br />većina nastavnika ima pozitivan stav prema<br />ovim aktivnostima.</p> / <p>The aim of this doctoral thesis is to<br />perform a comparative analysis of collaborative<br />and independent writing in primary-school EFL<br />teaching. Writing skill is considered to be a<br />complex cognitive language skill which has an<br />important role in the global community.<br />Therefore, it is essential to devote more time to<br />teaching writing. Writing used to be taught for<br />years as a product and not a process. Teachers<br />emphasized the importance of grammar and<br />spelling and not much attention was placed on<br />the content of the written text or the<br />organization of ideas inside it. In order to<br />enhance written expression, students need to get<br />involved in the learning process. Interaction is<br />emphasized as the key part of learning and it<br />increases collaboration during the lessons. The<br />collaboration process is equally important as the<br />writing process.<br />Peer collaboration and scaffolding<br />became the integral part of the English language<br />classroom and the aim of this thesis was to<br />check their effectiveness during the final years<br />of primary schools. The research was conducted<br />in 2014 with the students of the 8th grade.<br />During this research students had to do<br />individual writing and then they had writing<br />activities in groups. Error analysis of the<br />students&rsquo; essays proves that students in<br />collaborative writing make fewer errors and<br />write more coherent compositions In the second part of the research the</p><p>students expressed their attitudes towards<br />collaborative activities using questionnaires. It<br />is assumed that collaborative activities increase<br />motivation, enthusiasm and confidence among<br />learners. In addition to this survey, group<br />interviews were used as another research<br />technique. According to the results it can be<br />concluded that students prefer collaborative to<br />individual writing, but also that a lot of students<br />are uncertain about their attitudes. Furthermore,<br />in order to enhance collaboration during the<br />lessons it is necessary to teach students how to<br />effectively work in groups.<br />Teachers play an important role in the<br />students&rsquo; learning process and it largely depends<br />on them whether students consider writing to be<br />an interesting or exhausting part of the EFL<br />lesson. The last part of the research deals with<br />teacher&rsquo;s attitude to collaborative and individual<br />writing and the results show that most teachers<br />do have positive attitude towards collaboration.</p>

The Penman-Monteith (PM) equation is a state-of-the-art modelling approach to simulate evapotranspiration (ET) at site and local scale. However, its practical application is often restricted by the availability and quality of required parameters. One of these parameters is the canopy conductance. Long term measurements of evapotranspiration by the eddy-covariance method provide an improved data basis to determine this parameter by inverse modelling. Because this approach may also include evaporation from the soil, not only the ‘actual’ canopy conductance but the whole surface conductance (gc) is addressed. Two full cycles of crop rotation with five different crop types (winter barley, winter rape seed, winter wheat, silage maize, and spring barley) have been continuously monitored for 10 years. These data form the basis for this study. As estimates of gc are obtained on basis of measurements, we investigated the impact of measurements uncertainties on obtained values of gc. Here, two different foci were inspected more in detail. Firstly, the effect of the energy balance closure gap (EBCG) on obtained values of gc was analysed. Secondly, the common hydrological practice to use vegetation height (hc) to determine the period of highest plant activity (i.e., times with maximum gc concerning CO2-exchange and transpiration) was critically reviewed. The results showed that hc and gc do only agree at the beginning of the growing season but increasingly differ during the rest of the growing season. Thus, the utilisation of hc as a proxy to assess maximum gc (gc,max) can lead to inaccurate estimates of gc,max which in turn can cause serious shortcomings in simulated ET. The light use efficiency (LUE) is superior to hc as a proxy to determine periods with maximum gc. Based on this proxy, crop specific estimates of gc,maxcould be determined for the first (and the second) cycle of crop rotation: winter barley, 19.2 mm s−1 (16.0 mm s−1); winter rape seed, 12.3 mm s−1 (13.1 mm s−1); winter wheat, 16.5 mm s−1 (11.2 mm s−1); silage maize, 7.4 mm s−1 (8.5 mm s−1); and spring barley, 7.0 mm s−1 (6.2 mm s−1).

Cette recherche vise à décrire 1) les erreurs lexicales commises en production écrite par des élèves francophones de 3e secondaire et 2) le rapport à l’erreur lexicale d’enseignants de français (conception de l’erreur lexicale, pratiques d’évaluation du vocabulaire en production écrite, modes de rétroaction aux erreurs lexicales). Le premier volet de la recherche consiste en une analyse d’erreurs à trois niveaux : 1) une description linguistique des erreurs à l’aide d’une typologie, 2) une évaluation de la gravité des erreurs et 3) une explication de leurs sources possibles. Le corpus analysé est constitué de 300 textes rédigés en classe de français par des élèves de 3e secondaire. L’analyse a révélé 1144 erreurs lexicales. Les plus fréquentes sont les problèmes sémantiques (30%), les erreurs liées aux propriétés morphosyntaxiques des unités lexicales (21%) et l’utilisation de termes familiers (17%). Cette répartition démontre que la moitié des erreurs lexicales sont attribuables à une méconnaissance de propriétés des mots autres que le sens et la forme. L’évaluation de la gravité des erreurs repose sur trois critères : leur acceptation linguistique selon les dictionnaires, leur impact sur la compréhension et leur degré d’intégration à l’usage. Les problèmes liés aux registres de langue sont généralement ceux qui sont considérés comme les moins graves et les erreurs sémantiques représentent la quasi-totalité des erreurs graves. Le troisième axe d’analyse concerne la source des erreurs et fait ressortir trois sources principales : l’influence de la langue orale, la proximité sémantique et la parenté formelle entre le mot utilisé et celui visé. Le second volet de la thèse concerne le rapport des enseignants de français à l’erreur lexicale et repose sur l’analyse de 224 rédactions corrigées ainsi que sur une série de huit entrevues menées avec des enseignants de 3e secondaire. Lors de la correction, les enseignants relèvent surtout les erreurs orthographiques ainsi que celles relevant des propriétés morphosyntaxiques des mots (genre, invariabilité, régime), qu’ils classent parmi les erreurs de grammaire. Les erreurs plus purement lexicales, c’est-à-dire les erreurs sémantiques, l’emploi de termes familiers et les erreurs de collocation, demeurent peu relevées, et les annotations des enseignants concernant ces types d’erreurs sont vagues et peu systématiques, donnant peu de pistes aux élèves pour la correction. L’évaluation du vocabulaire en production écrite est toujours soumise à une appréciation qualitative, qui repose sur l’impression générale des enseignants plutôt que sur des critères précis, le seul indicateur clair étant la répétition. Les explications des enseignants concernant les erreurs lexicales reposent beaucoup sur l’intuition, ce qui témoigne de certaines lacunes dans leur formation en lien avec le vocabulaire. Les enseignants admettent enseigner très peu le vocabulaire en classe au secondaire et expliquent ce choix par le manque de temps et d’outils adéquats. L’enseignement du vocabulaire est toujours subordonné à des tâches d’écriture ou de lecture et vise davantage l’acquisition de mots précis que le développement d’une réelle compétence lexicale. / This research aims to describe 1) francophone students’ lexical errors in writing and 2) teachers’ relation to lexical errors (conception of error, vocabulary evaluation practices, feedback provided). The first part of the research consists in a three-level error analysis: 1) a linguistic description based on an error typology, 2) an evaluation of error gravity and 3) an explanation of the possible sources of error. The corpus analyzed is composed of 300 texts written in French class by 3rd year high school students. The analysis revealed 1144 lexical errors. The most common are semantic problems (30%), errors related to morphosyntactic properties of words (21%) and the use of colloquial words (17%). This distribution shows that half of the lexical errors are due to a lack of knowledge of word properties other than meaning and form. The evaluation of error gravity is based on three criteria: their acceptability according to dictionaries, their impact on comprehension and their degree of integration to language. Problems related to register are usually those perceived as less serious and semantic problems represent the vast majority of serious errors. The third level of analysis concerns the possible causes of the errors and identifies three main sources: influence of oral language, semantic proximity and formal similarity between the word used and the target word. The second part of the thesis concerns French teachers’ relation to lexical errors and is based on the analysis of 224 corrected essays and eight interviews. When correcting, teachers focus their attention on errors involving morphosyntactic properties of words (gender, invariability, government pattern), which they consider as grammatical errors. The more genuine lexical errors (semantic errors, use of colloquial words and collocation errors) are rarely pointed out, and comments provided regarding these types of errors are vague and inconsistent, giving students very few hints for correction. The evaluation of vocabulary in written production is always subject to a qualitative assessment, based on the teacher’s general impression rather than specific criteria, the only clear indicator being repetition. The explanations teachers provide about lexical problems rely heavily on intuition, which shows some deficiencies in their training in regards to vocabulary.

Notre constat de départ est que malgré un intérêt croissant des institutions enseignant les langues étrangères pour l’enseignement de la traduction, il n’existe à notre connaissance aucune étude portant sur la conception d’un programme de traduction professionnelle adapté à des apprenants de langues étrangères qui leur permettrait d’acquérir la compétence traductionnelle, c’est-à-dire les savoirs et savoir-faire nécessaires au traducteur en contexte professionnel. Ces institutions confondent souvent l’enseignement de la traduction et la traduction utilisée comme outil d’enseignement des langues étrangères. Le programme de traduction de l’université du Botswana ne fait pas exception, et nous proposons donc de le reconceptualiser afin qu’il réponde aux exigences de la profession. Par la mise à l’épreuve du modèle de l’analyse matricielle définitoire, outil linguistique destiné à interpréter et comparer la manière dont les langues naturelles construisent le sens, la présente thèse se propose de déceler les paramètres de l’environnement d’apprentissage sur lesquels une intervention est requise pour améliorer la qualité du programme et le rendre plus efficace. Pour ce faire, nous analyserons les erreurs de traduction commises par les étudiants qui suivent ce programme en vue d’en identifier les sources et de prendre les mesures destinées à en réduire la probabilité d’occurrence par la définition d’objectifs d’apprentissage adaptés à ce public, accompagnés des bases d’une solide assise théorique à destination de l’enseignant. / Our initial observation is that, in spite of the growing interest in teaching translation in institutions offering foreign language programmes, no study, to our knowledge, has been done on the designing of a professional translation programme appropriate for foreign language learners which could allow them to acquire translation competence, that is, knowledge and skills required by translators in a professional setting. These institutions often confuse teaching of translation and use of translation as a foreign language teaching tool. The translation programme of the University of Botswana is no exception, and we therefore propose to redesign it so that it can respond to the requirements of the profession. By putting to test the Defining Matrix Analysis model, a linguistic tool intended to interpret and compare the way natural languages construct sense, this thesis proposes to find the parameters of the learning environment on which an intervention is required in order to improve the quality and the efficiency of this programme. To achieve this goal, we are going to analyse translation errors made by students who are pursuing this translation programme with the aim of identifying their sources and taking measures destined to reduce their probability of occurrence by defining learning objectives adapted to this group of learners, accompanied by a solid theoretical basis for teachers.

Cette thèse s’inscrit au sein de la recherche sur l’analyse d’erreurs en espagnol langue seconde et dans une démarche d’enseignement de la langue à des apprenants non natifs dans le cadre universitaire français. A partir d’un corpus de données écrites centrées sur des productions dirigées en espagnol d’étudiants francophones spécialistes de l’université française, nous avons entrepris un travail d’analyse des erreurs des catégories grammaticales de l’espagnol pour en créer des types. En nous focalisant sur les typologies des erreurs lexico-orthographiques, lexico-sémantiques, lexico-syntaxiques et lexico-morphologiques, cette analyse a débouché sur un travail d’étiologie basé sur les erreurs d’interférence et de transfert négatif des langues connues de nos informateurs, erreurs les plus fréquentes. En vue d’une remédiation de ces erreurs pour le développement de la compétence linguistique voire plurilingue des apprenants, nous proposons des pistes didactiques tenant compte des objectifs et des compétences requises afin qu’ils acquièrent le niveau B1 du CECRL. / This work is about error analysis in Spanish as a second language and is aimed at improving language teaching to non-native learners in the French university system. Based on the study of a corpus of supervised written productions in Spanish from French-speaking specialist students in French universities, we analysed grammatical errors in Spanish in order to create an original typology. By focusing on the lexicon and the spelling, the lexicon and the semantics as well as lexical and morphological typologies of errors, this analysis allowed us to produce a work of etiology, mostly based on the errors of interference and negative transfer caused by the foreign languages already known to our students. So as to help the students deal with these errors and help them improve at their linguistic – and also multilingual – competences, we made didactic suggestions taking into account the goals and skills expected from students necessary to reach the B1 level of CECRL. / Esta tesis se inscribe en el seno de la investigación sobre el análisis de errores en español lengua segunda y en un enfoque de enseñanza de la lengua a aprendices no nativos en el marco universitario francés. A partir de un corpus de datos escritos centrados en producciones dirigidas en español de estudiantes francófonos especialistas de la universidad francesa, hemos iniciado un trabajo de análisis de los errores de las categorías gramaticales del español para crear diferentes tipos de ellas. Con el foco puesto en las tipologías de los errores léxico-ortográficos, léxico-semánticos, léxico-sintácticos y léxico-morfológicos, este análisis ha llevado a un trabajo de etiología basado en los errores de interferencia y transferencia negativa de las lenguas conocidas por nuestros informantes, errores más frecuentes. Con miras a una remediación de estos errores para lograr el desarrollo de la competencia linguística incluso plurilingüe de los aprendices, proponemos pistas didácticas teniendo en cuenta los objetivos y las competencias requeridas para que éstos adquieran el nivel B1 del CECRL.

Although Eduardo Mondlane University (UEM) has the longest history of BA Honours level translator and interpreter training in Mozambique, the university still lacks an effective model for the development of translation and interpreting competence in students. To address this problem, the present study seeks to find a practical model for the training of Mozambican professional translators and interpreters at BA Honours level that can guide the design of conducive curricula. The critical question the study attempts to answer is: What model for developing translation and interpreting competence could lead to an effective curriculum design that best meets the employment needs of Mozambican students? To this end, the study has been designed as action-research because this design enables better understanding and improvement of training processes (Cravo & Neves 2007). Three data collection tools are used to generate both qualitative and quantitative data from over 120 participants, namely: (i) a survey, (ii) an English translation test and (iii) a sample of archived Portuguese translations produced by former students. The survey findings suggest the need for a model whereby translators and interpreters are trained simultaneously within the same programme. Moreover, the results of macro- and micro-textual analysis show that, overall, the translation competence of former students is poor, suggesting that the current curriculum at UEM is failing to produce BA Honours translation/interpreting professionals. The proposed solution would be a curriculum based on a new integrated translation and interpreting competence development model with the following four pillars: communicative competence, general knowledge, strategic competence and service provision. / Nangona iyunivesithi iEduardo Mondlane University (UEM) inembali kwizifundo zesidanga esiphakamileyo (BA Honours) kuqeqesho lwabaguquleli neetoliki eMozambique, le yunivesithi ayikabi namzekelo unguwo nosebenzayo ekuphuhliseni izakhono zokuguqula nokutolika kubafundi bayo. Ukukhawulelana nale ngxaki olu phando lujolise ekufumaneni owona mzekelo usebenzayo onokusetyenziswa nonokuthi ube sisikhokelo kuyilo lwekharityhulam yesidanga esiphakamileyo iBA Honours esithatha iminyaka emine ekuqeqesheni abafundi babe ngabaguquleli neetoliki eziphume izandla zaseMozambique. Umbuzo ongundoqo nozanywa ukuphendulwa lolu phando ngulo: Ngowuphi umzekelo wokuphuhlisa izakhono zokuguqulela nokutolika onokukhokelela kuyilo lwekharityhulam esebenzayo nefezekisa iimfuno zengqesho zabafundi baseMozambique? Kungoko olu phando luye lwasebenzisa indlela yokuphanda ekuthiwa yi-action research eyenza kube lula ukuqonda nokuphucula iinkqubo zoqeqesho (Cravo & Neves 2007). Kuye kwasetyenziswa iindlela ezintathu zophando ukufumana ulwazi kubathathi-nxaxheba abali-120 ezizezi: (1) uvavanyo lwezimvo, (ii) uvavanyo lwenguqulelo yesicatshulwa esibhalwe ngesiNgesi kunye (iii) neenguqulelo zesiPhuthukezi ezenziwe ngabafundi bangaphambili ezigciniweyo. Iziphumo zeemvavanyo zezimvo zibonisa ukuba kufuneka kukho umzekelo onokusetyenziswa ekuqeqesheni abaguquleli neetoliki ngaxeshanye phantsi kwenkqubo enye. Ukongeza koku, iziphumo zohlalutyo lwesicatshulwa zibonise ukuba izakhono zokuguqulela zabafundi bangaphambili azikho mgangathweni, nto leyo ethetha ukuba ikharityhulam esetyenziswayo eUEM iyasilela ekukhupheni abaguquleli neetoliki ezinobuchule neziziincutshe. Isisombululo esicetyiswayo ke ngoko, sesokuba kubekho ikharityhulam ehlangeneyo eza kuphuhlisa izakhono zabaguquleli neetoliki esekelwe kwiintsika ezine ezizezi: isakhono sonxibelelwano, ulwazi jikelele, isakhono sobuchule kunye nokunikezwa kweenkonzo. / Nakuba iNyuvesi i-Eduardo Mondlane University (i-UEM) isinomlando omude kakhulu wokuqeqesha abahumushi notolika ezingeni leziqu ze-BA Honours eMozambique, le nyuvesi ayikabi nayo indlela esebenzayo yokuthuthukisa amakhono ezitshudeni kwezokuhumusha nokutolika. Ukubhekana nale nkinga lolu cwaningo kuhloswe ngalo ukuthola indlela esebenzayo yokuqeqesha ongoti babahumushi notolika baseMozambique ezingeni leziqu ze-BA Honours (iziqu zeminyaka emine) ezingahlahla indlela yokuklama uhlelo lwezifundo olungasiza kule nkinga. Umbuzo omkhulu lolu cwaningo oluzama ukuwuphendula ngothi: Iyiphi indlela yokuthuthukisa amakhono okuhumusha nokutolika engaholela ekuklanyweni kohlelo lwezifundo olungahlangabezana nezidingo zokuqasheka kwezitshudeni zaseMozambique? Ukufeza le nhloso, lolu cwaningo lusebenzisa uhlelo lokucwaninga olubizwa nge-action-research ngoba luyasiza ekuqondeni kangcono nasekuthuthukiseni inqubo yokuqeqesha (Cravo & Neves 2007). Kusetshenziswa amathuluzi amathathu okuqoqa imininingobunjalo nemininingobuningi evela kubabambiqhaza abangaphezu kwabayi-120, okuyilokhu: (i) ngohlolocwaningo (i-survey), (ii) ngesivivinyo sesihumusho sesiNgisi (iii) nangesampula lezihumusho zesiPutukezi zabafundi baphambilini. Okutholakale kulo uhlolocwaningo kuveza isidingo sendlela yokuqeqesha abahumushi notolika kanyekanye ohlelweni lokufundiswa olufanayo. Ngaphezu kwalokho, imiphumela yokuhlaziywa kwemibhalo nezimo eyabhalwa ngaphansi kwazo ibonisa ukuthi, ngokubanzi, amakhono okuhumusha abafundi baphambilini awamahle, okuyinkomba yokuthi uhlelo lwezifundo lwamanje e-UEM luyehluleka ukukhiqiza ongoti bokuhumusha nokutolika ezingeni le-BA Honours. Isixazululo esiphakanyiswayo ngesendlela entsha esuselwa ekuthuthukiseni amakhono edidiyela ukuhumusha nokutolika, enalezi zinsika ezine ezilandelayo: amakhono kwezokuxhumana, ulwazi ngokubanzi, ikhono lokusebenzisa amasu, nokuhlinzekwa kwezidingo. / Linguistics and Modern Languages / D. Phil. (Languages, Linguistics and Literature)

This thesis is concerned with methods for Bayesian inference and their applications in astrophysics. We principally discuss two related themes: advances in nested sampling (Chapters 3 to 5), and Bayesian sparse reconstruction of signals from noisy data (Chapters 6 and 7). Nested sampling is a popular method for Bayesian computation which is widely used in astrophysics. Following the introduction and background material in Chapters 1 and 2, Chapter 3 analyses the sampling errors in nested sampling parameter estimation and presents a method for estimating them numerically for a single nested sampling calculation. Chapter 4 introduces diagnostic tests for detecting when software has not performed the nested sampling algorithm accurately, for example due to missing a mode in a multimodal posterior. The uncertainty estimates and diagnostics in Chapters 3 and 4 are implemented in the $\texttt{nestcheck}$ software package, and both chapters describe an astronomical application of the techniques introduced. Chapter 5 describes dynamic nested sampling: a generalisation of the nested sampling algorithm which can produce large improvements in computational efficiency compared to standard nested sampling. We have implemented dynamic nested sampling in the $\texttt{dyPolyChord}$ and $\texttt{perfectns}$ software packages. Chapter 6 presents a principled Bayesian framework for signal reconstruction, in which the signal is modelled by basis functions whose number (and form, if required) is determined by the data themselves. This approach is based on a Bayesian interpretation of conventional sparse reconstruction and regularisation techniques, in which sparsity is imposed through priors via Bayesian model selection. We demonstrate our method for noisy 1- and 2-dimensional signals, including examples of processing astronomical images. The numerical implementation uses dynamic nested sampling, and uncertainties are calculated using the methods introduced in Chapters 3 and 4. Chapter 7 applies our Bayesian sparse reconstruction framework to artificial neural networks, where it allows the optimum network architecture to be determined by treating the number of nodes and hidden layers as parameters. We conclude by suggesting possible areas of future research in Chapter 8.

Energy usage evaluation and condition monitoring for electric machines are important in industry for overall energy savings. Traditionally these functions are realized only for large motors in wired systems formed by communication cables and various types of sensors. The unique characteristics of the wireless sensor networks (WSN) make them the ideal wireless structure for low-cost energy management in industrial plants. This work focuses on developing nonintrusive motor-efficiency-estimation methods, which are essential in the wireless motor-energy-management systems in a WSN architecture that is capable of improving overall energy savings in U.S. industry. This work starts with an investigation of existing motor-efficiency-evaluation methods. Based on the findings, a general approach of developing nonintrusive efficiency-estimation methods is proposed, incorporating sensorless rotor-speed detection, stator-resistance estimation, and loss estimation techniques. Following this approach, two new methods are proposed for estimating the efficiencies of in-service induction motors, using air-gap torque estimation and a modified induction motor equivalent circuit, respectively. The experimental results show that both methods achieve accurate efficiency estimates within ¡À2-3% errors under normal load conditions, using only a few cycles of input voltages and currents. The analytical results obtained from error analysis agree well with the experimental results. Using the proposed efficiency-estimation methods, a closed-loop motor-energy-management scheme for industrial plants with a WSN architecture is proposed. Besides the energy-usage-evaluation algorithms, this scheme also incorporates various sensorless current-based motor-condition-monitoring algorithms. A uniform data interface is defined to seamlessly integrate these energy-evaluation and condition-monitoring algorithms. Prototype wireless sensor devices are designed and implemented to satisfy the specific needs of motor energy management. A WSN test bed is implemented. The applicability of the proposed scheme is validated from the experimental results using multiple motors with different physical configurations under various load conditions. To demonstrate the validity of the measured and estimated motor efficiencies in the experiments presented in this work, an in-depth error analysis on motor efficiency measurement and estimation is conducted, using maximum error estimation, worst-case error estimation, and realistic error estimation techniques. The conclusions, contributions, and recommendations are summarized at the end.

published_or_final_version / Language Studies / Master / Master of Arts

published_or_final_version / Education / Master / Master of Education