A naïve, salience-based method for speaker identification in fiction books

This paper presents a salience-based technique for the annotation of directly quoted speech from fiction text. In particular, this paper determines to what extent a naïve (without the use of complex machine learning or knowledge-based techniques) scoring technique can be used for the identification of the speaker of speech quotes. The presented technique makes use of a scoring technique, similar to that commonly found in knowledge-poor anaphora resolution research, as well as a set of hand-coded rules for the final identification of the speaker of each quote in the text. Speaker identification is shown to be achieved using three tasks: the identification of a speech-verb associated with a quote with a recall of 94.41%; the identification of the actor associated with a quote with a recall of 88.22%; and the selection of a speaker with an accuracy of 79.40%.

The ontogeny of naïve and regulatory CD4(+) T-cell subsets during the first postnatal year: a cohort study

As there is limited knowledge regarding the longitudinal development and early ontogeny of naïve and regulatory CD4(+) T-cell subsets during the first postnatal year, we sought to evaluate the changes in proportion of naïve (thymic and central) and regulatory (resting and activated) CD4(+) T-cell populations during the first postnatal year. Blood samples were collected and analyzed at birth, 6 and 12 months of age from a population-derived sample of 130 infants. The proportion of naïve and regulatory CD4(+) T-cell populations was determined by flow cytometry, and the thymic and central naïve populations were sorted and their phenotype confirmed by relative expression of T cell-receptor excision circle DNA (TREC). At birth, the majority (94%) of CD4(+) T cells were naïve (CD45RA(+)), and of these, ~80% had a thymic naïve phenotype (CD31(+) and high TREC), with the remainder already central naïve cells (CD31(-) and low TREC). During the first year of life, the naïve CD4(+) T cells retained an overall thymic phenotype but decreased steadily. From birth to 6 months of age, the proportion of both resting naïve T regulatory cells (rTreg; CD4(+)CD45RA(+)FoxP3(+)) and activated Treg (aTreg, CD4(+)CD45RA(-)FoxP3(high)) increased markedly. The ratio of thymic to central naïve CD4(+) T cells was lower in males throughout the first postnatal year indicating early sexual dimorphism in immune development. This longitudinal study defines proportions of CD4(+) T-cell populations during the first year of postnatal life that provide a better understanding of normal immune development.

Recrystallization textures in course grained low carbon and interstitial free steels

The microstructures and textures of coarse grained cold rolled, partially recrystallized and fully recrystallized low carbon and interstitial free steel were examined by optical microscopy, scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The recrystallization textures of the two grades are markedly different, with the low carbon steel having a predominantly Goss {11O}<OOl> texture and the interstitial free steel having a <1ll>/1ND texture with a strong {III }<112> component. One possible explanation for the texture difference is that less severe localization of flow during deformation of interstitial free steels causes less Goss nuclei to be generated. While some support for this view is provided by the results presented in this paper, the results suggest that another mechanism may be at least partially responsible. Examination of micro
shear bands on the surface of pre-polished samples showed that a higher proportion of micro shear bands remained active at high rolling reductions in the low carbon steel, compared with the interstitial free grade. Regions of Goss orientation within bands that have ceased to operate rotate to
near-{ III }<112> orientations with further deformation. Consequently, the recrystallization texture of coarse grained interstitial free steels can be rationalized by a reduction in the availability of Goss nuclei and an increase in the availability of {Ill }<112> nuclei due to a "Goss to {Ill }<112>" rotation within micro shear bands that have ceased to operate.

Method for determining reaction rate of mild steel containers during melting of magnesium-aluminium alloys and effect of aluminium content on directionally solidified microstructures

A magnesium alloy of eutectic composition (33 wt-'%Al) was directionally solidified in mild steel tubes at two growth rates, 32 and 580 mum s(-1,) in a temperature gradient between 10 and 20 K mm(-1). After directional solidification, the composition of each specimen varied dramatically, from 32'%Al in the region that had remained solid to 18%Al (32 mum s(-1) specimen) and 13%Al (580 mum s(-1) specimen) at the plane that had been quenched from the eutectic temperature. As the aluminium content decreased, the microstructure contained an increasing volume fraction of primary magnesium dendrites and the eutectic morphology gradually changed from lamellar to partially divorced. The reduction in aluminium content was caused by the growth of an Al-Fe phase ahead of the Mg-Al growth front. Most of the growth of the Al-Fe phase occurred during the remelting period before directional solidification. The thickness of the Al-Fe phase increased with increased temperature and time of contact with the molten Mg-Al alloy. (C) 2003 Maney Publishing.

Fragmentation of orientation within grains of a cold-rolled interstitial-free steel

The formation of a favourable recrystallization texture in interstitial-free (IF) steels depends on the availability and activation of particular nucleation sites in the deformed microstructure. This paper presents a description of the deformed microstructure of a commercially cold-rolled IF steel, with particular emphasis on the microstructural inhomogeneities and short-range orientational variation that provide suitable nucleation sites during recrystallization. RD-fibre regions deform relatively homogeneously and exhibit little short-range orientational variation. ND-fibre regions are heavily banded and exhibit considerable short-range orientational variation associated with the bands. While the overall orientational spread of ND-fibre grains frequently is about the ND-axis, the short-range orientational variation often involves rotation about axes in the TD-ND plane that are nearer to the TD than the ND.

The influence of solute carbon in cold-rolled steels on shear band formation and recrystallization texture

Two experiments were conducted to clarify the roles of grain size, solute carbon and strain in determining the recrystallization textures of cold-rolled and annealed steels. In the first experiment, samples of coarse-grained low-carbon (LC) and interstitial-free (IF) steels were cold-rolled to a 75% reduction in thickness. One sample from each steel was polished and cold-rolled an additional 5%, while the remaining samples were annealed for various times at 650°C. In the second experiment, three samples from a commercial LC steel sheet were rolled 70% at 300°C. Two of the samples were given a further rolling reduction of 5% of the original thickness, with one of the samples being given this additional reduction at 300°C and the other at room temperature. Goss recrystallization textures are strengthened by coarse initial grain sizes, the presence of solute carbon and rolling at a temperature where dynamic strain ageing occurs, but are weakened by additional rolling beyond a reduction of 70%, especially when this extra rolling is conducted at a temperature where dynamic strain ageing does not occur. Characterization of key features of the deformed and recrystallized steels using optical microscopy, scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD) supports a rationale for these effects based on the repeated activation and deactivation of shear bands and the influence of solute carbon and dynamic strain ageing on the operating life of the bands and the accumulation of strain within them.

On the production of randomly-oriented recrystallization nuclei for selective growth experiments

The ideal starting condition for selective growth experiments is one having a layer of randomly-oriented nuclei adjacent to a matrix with negligible orientational variation but sufficient stored energy to promote growth. In practice, cutting or deformation processes are used in an attempt to approximate these ideal conditions, but the degree to which this is achieved has not been rigorously quantified. In this work, Fe-3wt%Si single crystals were cut or deformed using six different processes. The variation in texture with distance from the cut or deformed surface was measured using electron backscatter diffraction (EBSD) in a field emission gun scanning electron microscope (FEG-SEM) in order to assess the ability of each process to create conditions suitable for selective growth experiments. While grooving with a machine tool produced the best spread of orientations at the cut surface, the suitability of this process is diminished by the presence of a differently-textured deformed layer between the cut surface and the single crystal matrix. Grinding produced a less ideal distribution of orientations at the cut surface, but the presence of these orientations in a very thin layer adjacent to the matrix makes this process preferable for preparing crystals for selective growth experiments, provided the results are corrected for the deviation in the distribution of nuclei orientations from a random distribution.

Understanding the deformed microstructure of cold-rolled IF and LC steel

This paper presents an overview of a series of investigations of the microstructure and texture of cold-rolled IF and LC steel. The investigations made extensive use of orientation mapping using electron backscattered diffraction (EBSD) in a field emission gun scanning electron microscope (FEG-SEM). The effect of grain boundaries on the deformed microstructure was examined by comparing the textures of regions near grain boundaries and in the interiors of grains.  A general weakening of the texture, but a strengthening of the {OOI}<110> component, occurs in the vicinity of grain boundaries. Misorientation angle and axis distributions were used to characterise the fragmentation of grains belonging to different orientation classes. The influence of carbon on the deformed microstructure and nucleation during recrystallization was clarified by examining the microstructures of LC and IF steels during rolling and annealing. The
results of the investigations emphasize the important role of shear banding in determining the fragmentation behaviour of ND-fibre grains and the orientations of viable recrystallization nuclei within the deformed microstructure.

Microstructural features of rolled mg-3Al-1Zn

The microstructures of hot- and cold-rolled Mg-3Al-1Zn (AZ31) are examined using scanning electron and optical microscopy. It is shown that the microstructures following multipass hot rolling and annealing are more uniform than those formed by heavy single pass rolling and annealing. The importance of twins in producing intragranular recrystallization is evident, although the most dominant nucleation site is grain boundaries. The cold-rolled structure after a rolling reduction of 15 pct is dominated by the presence of deformation twins. Twin trace analysis suggests that approximately two thirds of the twins are a form of “c-axis compression” twin. A number of “c-axis tension” twins were also observed and additional in-situ scanning electron microscopy experiments were performed to confirm earlier observations that suggest these twins can form after deformation, during unloading.

Evaluation of selective growth in a Fe-2.8% Si single crystal using Rodrigues-Frank space

A Fe-2.8%Si single crystal was scratched in order to randomise the texture in the neighbourhood of the notch. Annealing resulted in recrystallization and grain growth starting from the deformed zone. Misorientations between the single crystal matrix and the grown grains were gathered and were studied in order to investigate the possibility for selective growth based on a specific misorientation. However, instead of studying the misorientation angle or axis profiles separately in a 1D or 2D projection a full misorientation analysis was carried out in the 3-dimensional Rodrigues-Frank misorientation space, which offers an unambiguous interpretation of the data because no features are hidden or masked by a projection. It is concluded that the selective growth phenomenon following the <110>26.5deg misorientation relationship is strongly supported by the gathered orientation data, after appropriately normalizing these data with respect to a random misorientation distribution.

Cracking and blowout in an aluminium high-pressure die casting die

Die cracking and metal blowout have been identified as problems in production of the structural sump, a high pressure die cast aluminium part, at Ford's Geelong manufacturing plant. Visual inspection, thermography and strain measurements have been performed and results are consistent with the view that cracking and blowout are caused by excessive stresses and deflections, respectively, generated by bending of the sliding cores. Models are being developed for finite element simulation of the stresses and deflections in the die during production, with a view to eliminating the aforementioned problems.