Flow and combustion in axisymmetric furnaces

Imperial Users onl

Supertagged phrase-based statistical machine translation

Until quite recently, extending Phrase-based Statistical Machine Translation (PBSMT) with syntactic structure caused system performance to deteriorate. In this work we show that incorporating lexical syntactic descriptions in the form of supertags can yield significantly better PBSMT systems. We describe a novel PBSMT model that integrates supertags into the target language model and the target side of the translation model. Two kinds of supertags are employed: those from Lexicalized Tree-Adjoining Grammar and Combinatory Categorial Grammar. Despite the differences between these two approaches, the supertaggers give similar improvements. In addition to supertagging, we also explore the utility of a surface global grammaticality measure based on combinatory operators. We perform various experiments on the Arabic to English NIST 2005 test set addressing issues such as sparseness, scalability and the utility of system subcomponents. Our best result (0.4688 BLEU) improves by 6.1% relative to a state-of-theart PBSMT model, which compares very favourably with the leading systems on the NIST 2005 task

A syntactified direct translation model with linear-time decoding

Recent syntactic extensions of statistical translation models work with a synchronous context-free or tree-substitution grammar extracted from an automatically parsed parallel corpus. The decoders accompanying these extensions typically exceed quadratic time complexity. This paper extends the Direct Translation Model 2 (DTM2) with syntax while maintaining linear-time decoding. We employ a linear-time parsing algorithm based on an eager, incremental interpretation of Combinatory Categorial Grammar (CCG). As every input word is processed, the local parsing decisions resolve ambiguity eagerly, by selecting a single supertag–operator pair for extending the dependency parse incrementally. Alongside translation features extracted from the derived parse tree, we explore syntactic features extracted from the incremental derivation process. Our empirical experiments show that our model significantly outperforms the state-of-the art DTM2 system

A syntactic language model based on incremental CCG parsing

Syntactically-enriched language models (parsers) constitute a promising component in applications such as machine translation and speech-recognition. To maintain a useful level of accuracy, existing parsers are non-incremental and must span a combinatorially growing space of possible structures as every input word is processed. This prohibits their incorporation into standard linear-time decoders. In this paper, we present an incremental, linear-time dependency parser based on Combinatory Categorial Grammar (CCG) and classification techniques. We devise a deterministic transform of CCGbank canonical derivations into incremental ones, and train our parser on this data. We discover that a cascaded, incremental version provides an appealing balance between efficiency and accuracy

Syntactic phrase-based statistical machine translation

Phrase-based statistical machine translation (PBSMT) systems represent the dominant approach in MT today. However, unlike systems in other paradigms, it has proven difficult to date to incorporate syntactic knowledge in order to improve translation quality. This paper improves on recent research which uses 'syntactified' target language phrases, by incorporating supertags as constraints to better resolve parse tree fragments. In addition, we do not impose any sentence-length limit, and using a log-linear decoder, we outperform a state-of-the-art PBSMT system by over 1.3 BLEU points (or 3.51% relative) on the NIST 2003 Arabic-English test corpus

Syntactic aspects of Poetry: A Pragmatic Perspective

This paper is meant to review some studies and analyses that deal with the language of poetry as it is different from the language of other literary genres.  Poetry consists of language that produces effects ordinary language does not produce. So poetry is a language differently ordered or arranged. Levin (1969) pointed out that linguistic analysis, when applied to poetry, would result in a grammar that is different from the grammar that a linguistic analysis of ordinary language would produce (11).The language of poetry differs drastically from ordinary discourse. Many of these differences derive from certain literary conventions. In other words, many features distinguishing poetry from ordinary discourse result from the mere fact that a writer addresses himself to writing a poem.  This fact entails a considerable number and variety of linguistic particularities. The conventions of the poetic form entail features like rhyme, alliteration, meter and so on (Levin 59)

Arab EFL learners' attitudes towards and perceptions of English culture and their achievement in English.

SIGLEAvailable from British Library Document Supply Centre- DSC:DX180704 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Synthesis of aerogels, nanocomposites and lightweight silica aerogel superinsulation nanocomposites by ambient pressure drying method

Ph. D ThesisThis thesis mainly investigates the improvement of the new ambient pressure approach used to synthesise aerogels by using a solvent comprising of sodium bicarbonate and water instead of a low surface tension solvent. Firstly, to improve the efficiency of thermal insulation, the sodium bicarbonate approach is utilised to synthesise cost effective ceramic blanket silica aerogels (CBSA) and short ceramic fibres silica aerogel composites (CSSA). To reduce the manufacturing cost and scalable of silica aerogels, we propose applying the sodium bicarbonate approach to synthesis silica aerogels from sodium silicate (water glass) precursor. In addition, the approach is used to synthesise alumina-based aerogel (dawsonite-sodium aluminium carbonate hydroxide) from Aluminium sec-butoxide precursor (ASB). To mimic the structure and thickness of the wings of the damselfly, which was the main source of inspiration for this study, multi-layered silica aerogel films with a thickness of 0.3 mm were synthesised using the bicarbonate approach. Finally, wavy nickel nanowires (NiNWs) were synthesise and immobilised on mesoporous silica (SiO2) aerogels by the sol-gel method. In addition, nickel nanoparticles (NiNPs) were immobilised in silica aerogels to do a comparative study between the catalytic activity of immobilised NiNWs and NiNPs in silica aerogels for CO2 hydration reaction (CHR) in gaseous phase. Dynamic vapour sorption (DVS) analysis is used for that purpose. The analysis is performed at levels of 50% CO2 and 50% H2O vapour for SiO2 aerogels, immobilised nickel nanoparticles (NiNPs) on silica aerogels and NiNWs-SiO2 aerogels composites. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), uniaxial compression test, Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods are used to characterise the synthesised materials

Relationships between Extension Competencies, Organisational Commitment and Job Satisfaction with Performance of Agricultural Extension Workers in Yemen

This study aimed to determine the relationships between selected variables, namely extension competencies including human development competencies, leadership development, extension communication methods, programme development, programme implementation and programme evaluation; organisational commitment as well as job satisfaction and job performance of agriculture extension workers. The study also sought to identify the best predictors of job performance of the extension workers. The total population of the extension workers was 1364. The sample size of this study was 300 which were determined by using Cochran's formula (1977). The study used stratified random sampling technique in which 300 respondents from the agriculture extension services organisations in Yemen were chosen. A complete list of agriculture extension workers across the three agriculture regions, namely, coastal, highlands and desert regions was obtained. The research design of this study was a descriptive correlational study. Self-administered questionnaire was used as the research instrument to collect data from the respondents of this study. The quantitative data were analysed by using descriptive statistics such as mean and standards deviations. The parametric statistics such as Pearson correlation, multiple regression analyses, t-test and ANOVA also were used. From the descriptive analysis, the result show that the overall extension workers performance illustrated with mean score (M = 2.88) and standard deviation (SD = 0.69), that more than a half (60.7 %) of the respondents experienced a moderate level of job performance, while 23.8 % of them indicated a low level of performance and 15.5% considered a high level of performance. Furthermore, the findings from parametric analysis indicated that there were significant relationships between the independent variables and job performance of extension workers. The independent variables are as follows: extension programme implementation competencies, extension programme planning competencies, extension programme evaluation competencies, organisational commitment, and job satisfaction. Multiple regression analysis was used to identify the best predictors of extension workers’ performance. The variables according to descending order are job satisfaction (Beta = 0.431), extension programme planning competencies (Beta = 0.239), extension programme implementation competencies (Beta = 0.147), extension programme evaluation competencies (Beta = 0.145), and organisational commitment (Beta = 0.102). The predictors explained 60.6 % variance (F = 54.008, p = 0.0001) of job performance. The study is important as it would become a platform for future research to consider aspect of performance and its variants. The implementation of human resource development initiatives is very important to consider by the relevant agencies in order to improve extension workers’ competencies and performance. This study also signals the importance of ensuring good and motivated work environment for extension workers for achieving a high performance. Extension services should also realise the various contributors of job performance, some of them are based on the individual factors as found in this study. By knowing these factors, they would be used as inputs in the recruitment, selection and succession planning processes in order to get the right extension workers. This will make extension workers know clearly their duties, tasks, and how to act in rural community. To support the findings of this study in the country, it is recommended that future studies are conducted across employees from other rural development organisations including agricultural and community development organisations by taking into considerations other work behaviour and social factors that might help more to understand the individual performance phenomenon