Pultrusion process characterization

Pultrusion is a process through which high-modulus, lightweight composite structural members such as beams, truss components, stiffeners, etc., are manufactured. The pultrusion process, though a well-developed processing art, lacks a fundamental scientific understanding. The objective here was to determine, both experimentally and analytically, the process parameters most important in characterizing and optimizing the pultrusion of uniaxial fibers. The effects of process parameter interactions were experimentally examined as a function of the pultruded product properties. A numerical description based on these experimental results was developed. An analytical model of the pultrusion process was also developed. The objective of the modeling effort was the formulation of a two-dimensional heat transfer model and development of solutions for the governing differential equations using the finite element method

Determination of wind tunnel constraint effects by a unified pressure signature method. Part 2: Application to jet-in-crossflow

The development of an improved jet-in-crossflow model for estimating wind tunnel blockage and angle-of-attack interference is described. Experiments showed that the simpler existing models fall seriously short of representing far-field flows properly. A new, vortex-source-doublet (VSD) model was therefore developed which employs curved trajectories and experimentally-based singularity strengths. The new model is consistent with existing and new experimental data and it predicts tunnel wall (i.e. far-field) pressures properly. It is implemented as a preprocessor to the wall-pressure-signature-based tunnel interference predictor. The supporting experiments and theoretical studies revealed some new results. Comparative flow field measurements with 1-inch "free-air" and 3-inch impinging jets showed that vortex penetration into the flow, in diameters, was almost unaltered until 'hard' impingement occurred. In modeling impinging cases, a 'plume redirection' term was introduced which is apparently absent in previous models. The effects of this term were found to be very significant

The Use of yig-cha and chos-kyi-rnam-grangs in Computing Lexical Cohesion for Tibetan Topic Boundary Detection

To properly implement a simple Tibetan Information Retrieval (IR) system segmentation of one form or another (n-gram, POS-tagging, dictionary substring matching, etc.) must be performed (see Hackett (2000b)). To take Tibetan indexing to a more sophisticated level however, some form of topic detection must be employed. This paper reports the results of a pilot study on the application to Tibetan of one technique for topic boundary detection: Lexical Cohesion. The resources developed and deployed, the theoretical model used, and its potential applications are discussed

Automatic Segmentation and Part-Of-Speech Tagging For Tibetan: A First Step Towards Machine Translation

This paper presents what we believe to be the first reported work on Tibetan machine translation (MT). Of the three conceptually distinct components of a MT system — analysis, transfer, and generation — the first phase, consisting of POS tagging has been successfully completed. The combination POS tagger / word-segmenter was manually constructed as a rule-based multi-tagger relying on the Wilson formulation of Tibetan grammar. Partial parsing was also performed in combination with POS-tag sequence disambiguation. The component was evaluated at the task of document indexing for Information Retrieval (IR). Preliminary analysis indicated slightly better (though statistically comparable) performance to n-gram based approaches at a known-item IR task. Although segmentation is application specific, error analysis placed segmentation accuracy at 99%; the accuracy of the POS tagger is also estimated at 99% based on IR error analysis and random sampling

Determination of wind tunnel constraint effects by a unified pressure signature method. Part 1: Applications to winged configurations

A new, fast, non-iterative version of the "Wall Pressure Signature Method" is described and used to determine blockage and angle-of-attack wind tunnel corrections for highly-powered jet-flap models. The correction method is complemented by the application of tangential blowing at the tunnel floor to suppress flow breakdown there, using feedback from measured floor pressures. This tangential blowing technique was substantiated by subsequent flow investigations using an LV. The basic tests on an unswept, knee-blown, jet flapped wing were supplemented to include the effects of slat-removal, sweep and the addition of unflapped tips. C sub mu values were varied from 0 to 10 free-air C sub l's in excess of 18 were measured in some cases. Application of the new methods yielded corrected data which agreed with corresponding large tunnel "free air" resuls to within the limits of experimental accuracy in almost all cases. A program listing is provided, with sample cases

An Entropy-based Assessment of the Unicode Encoding for Tibetan

This paper presents an analysis of the Unicode encoding scheme for Tibetan from the standpoint of morpheme entropy. We can speak of two levels of entropy in Tibetan: syllable entropy (a measure of the probability of the sequential occurrence of syllables), and morpheme entropy (a measure of the probability of the sequential occurrence of characters or morphemes), the latter being a measure of the redundancy of the language. Syllable entropy is a purely statistical calculation that is a function of the domain of the literature sampled, while morpheme entropy, we show, is relatively domain independent given a statistically significant sample. Morpheme entropy can be calculated statistically, though a theoretical upper bound can also be postulated based on language dependent morphology rules. This paper presents both theoretical and statistical estimates of the morpheme entropy for Tibetan, and explores the Tibetan Unicode encoding scheme in relation to data compression, and other issues analyzed in light of entropy-based language modeling

Developing a service user informed intervention to improve participation and ability to perform daily activities in primary Sjögren’s syndrome: a mixed-methods study protocol

Introduction: A significant proportion of patients with primary Sjögren’s syndrome (PSS) is functionally impaired and experience difficulties participating in various aspects of everyday life. There is currently no evidence of efficacy for non-pharmacological interventions aimed specifically at supporting the patients with PSS to improve their participation and ability to perform daily activities. This paper describes a research protocol for a mixed-methods study to develop an intervention to improve these outcomes. The protocol follows the Medical Research Council framework for complex interventions. Methods and analysis: We will use group concept mapping with the patients, adults who live with them and healthcare professionals to identify factors which prevent people with PSS from participating in daily life and performing daily activities. The factors will be prioritised by participants for importance and feasibility and will inform an intervention to be delivered within a National Health Service (NHS) setting. Evidence-based intervention techniques will be identified for the prioritised factors and combined into a deliverable intervention package. Key stakeholders will comment on the intervention content and mode of delivery through focus groups, and the data will be used to refine the intervention. The acceptability and feasibility of the refined intervention will be evaluated in a future study. Ethics and dissemination: The study has been approved by an NHS Research Ethics Committee, REC Reference: 13/NI/0190. The findings of this study will be disseminated in peer-reviewed journals and through presentation at national and international conferences. Trial registration number: UKCRN Study ID: 15939

An Entropy-based Assessment of the Unicode Encoding for Tibetan

This paper presents an analysis of the Unicode encoding scheme for Tibetan from the standpoint of morpheme entropy. We can speak of two levels of entropy in Tibetan: syllable entropy (a measure of the probability of the sequential occurrence of syllables), and morpheme entropy (a measure of the probability of the sequential occurrence of characters or morphemes), the latter being a measure of the redundancy of the language. Syllable entropy is a purely statistical calculation that is a function of the domain of the literature sampled, while morpheme entropy, we show, is relatively domain independent given a statistically significant sample. Morpheme entropy can be calculated statistically, though a theoretical upper bound can also be postulated based on language dependent morphology rules. This paper presents both theoretical and statistical estimates of the morpheme entropy for Tibetan, and explores the Tibetan Unicode encoding scheme in relation to data compression, and other issues analyzed in light of entropy-based language modeling

Document Translation for Cross-Language Text Retrieval at the University of Maryland

The University of Maryland participated in three TREC-6 tasks: ad hoc retrieval, cross-language retrieval, and spoken document retrieval. The principal focus of the work was evaluation of a cross-language text retrieval technique based on fully automatic machine translation. The results show that approaches based on document translation can be approximately as effective as approaches based on query translation, but that additional work will be needed to develop a solid basis for choosing between the two in specific applications. Ad hoc and spoken document retrieval results are also presented

Mustard catch crop enhances denitrification in shallow groundwater beneath a spring barley field

The study was funded by Department of Agriculture and Food through the Research Stimulus Fund Programme (Grant RSF 06383) in collaboration with the Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland.peer-reviewedOver-winter green cover crops have been reported to increase dissolved organic carbon (DOC) concentrations in groundwater, which can be used as an energy source for denitrifiers. This study investigates the impact of a mustard catch crop on in situ denitrification and nitrous oxide (N2O) emissions from an aquifer overlain by arable land. Denitrification rates and N2O-N/(N2O-N + N2-N) mole fractions were measured in situ with a push–pull method in shallow groundwater under a spring barley system in experimental plots with and without a mustard cover crop. The results suggest that a mustard cover crop could substantially enhance reduction of groundwater nitrate NO3--N via denitrification without significantly increasing N2O emissions. Mean total denitrification (TDN) rates below mustard cover crop and no cover crop were 7.61 and 0.002 μg kg−1 d−1, respectively. Estimated N2O-N/(N2O-N + N2-N) ratios, being 0.001 and 1.0 below mustard cover crop and no cover crop respectively, indicate that denitrification below mustard cover crop reduces N2O to N2, unlike the plot with no cover crop. The observed enhanced denitrification under the mustard cover crop may result from the higher groundwater DOC under mustard cover crop (1.53 mg L−1) than no cover crop (0.90 mg L−1) being added by the root exudates and root masses of mustard. This study gives insights into the missing piece in agricultural nitrogen (N) balance and groundwater derived N2O emissions under arable land and thus helps minimise the uncertainty in agricultural N and N2O-N balances