Multi-atlas segmentation (MAS) has become an established technique for the automated delineation of anatomical structures. The often manually annotated labels from each of multiple pre-segmented images (atlases) are typically transferred to a target through the spatial mapping of corresponding structures of interest. The mapping can be estimated by pairwise registration between each atlas and the target or by creating an intermediate population template for spatial normalisation of atlases and targets. The former is done at runtime which is computationally expensive but provides high accuracy. In the latter approach the template can be constructed from the atlases offline requiring only one registration to the target at runtime. Although this is computationally more efficient, the composition of deformation fields can lead to decreased accuracy. Our goal was to develop a MAS method which was both efficient and accurate. In our approach we create a target-specific template (TST) which has a high similarity to the target and serves as intermediate step to increase registration accuracy. The TST is constructed from the atlas images that are most similar to the target. These images are determined in low-dimensional manifold spaces on the basis of deformation fields in local regions of interest. We also introduce a clustering approach to divide atlas labels into meaningful sub-regions of interest and increase local specificity for TST construction and label fusion. Our approach was tested on a variety of MR brain datasets and applied to an in-house dataset. We achieve state-of-the-art accuracy while being computationally much more efficient than competing methods. This efficiency opens the door to the use of larger sets of atlases which could lead to further improvement in segmentation accuracy.

Biological vision and computational models of vision can be split into three independent components (image description, decision process, and image set). The thesis presented here aimed to investigate the influence of each of these core components on computational model’s similarity to human behaviour. Chapter 3 investigated the similarity of different computational image descriptors to their biological counterparts, using an image matching task. The results showed that several of the computational models could explain a significant amount of the variance in human performance on individual images. The deep supervised convolutional neural net explained the most variance, followed by GIST, HMAX and then PHOW. Chapter 4 investigated which computational decision process best explained observers’ behaviour on an image categorization task. The results showed that Decision Bound theory produced behaviour the closest to that of observers. This was followed by Exemplar theory and Prototype theory. Chapter 5 examined whether the naturally differing image set between computational models and observers could partially account for the difference in their behaviour. The results showed that, indeed, the naturally differing image set between computational models and observers was affecting the similarity of their behaviour. This gap did not alter which image descriptor best fit observers’ behaviour and could be reduced by training observers on the image set the computational models were using. Chapter 6 investigated, using computational models of vision, the impact of the neighbouring (masking) images on the target images in a RSVP task. This was done by combining the neighbouring images with the target image for the computational models’ simulation for each trial. The results showed that models behaviour became closer to that of the human observers when the neighbouring mask images were included in the computational simulations, as would be expected given an integration period for neural mechanisms. This thesis has shown that computational models can show quite similar behaviours to human observers, even at the level of how they perform with individual images. While this shows the potential utility in computational models as a tool to study visual processing, It has also shown the need to take into account many aspects of the overall model of the visual process and task; not only the image description, but the task requirements, the decision processes, the images being used as stimuli and even the sequence in which they are presented.

Handling large displacement optical flow is a remarkably arduous task. For instance, standard coarse-to-fine techniques often struggle to adequately deal with moving objects whose motion exceeds their size. Here we propose a learning approach to the estimation of large displacement between two non-consecutive images in a sequence on the basis of a learning set of optical flows estimated a priori between different consecutive images in the same sequence. Our method refines an initial estimate of the flow field by replacing each displacement vector by a linear combination of displacement vectors at the center of similar patches taken from a code-book built from the learning set. The key idea is to use the accurate flows estimated a priori between consecutive images to help improve the potentially less accurate flows estimated online between images further apart. Experimental results suggest the ability of a purely data-driven learning approach to handle fine scale structures with large displacements.

The purpose of this study was (1) to determine the need of phonics as a tool in word recognition; (2) to find out the opinions of outstanding educators concerning the value of phonics in primary reading; (3) to know present trends in the teaching of phonics in primary grades; and (4) to ascertain by actual experiment the results of phonetic training.

<p>Literacy is an important part of communication. Phonological awareness, i.e. the ability to recognise the sound units of language and to manipulate them, has been found to be crucial in literacy acquisition.</p><p>In 2005 the development of a communication device, a talking joystick called the PhonicStick, started at The School of Computing at the University of Dundee in Scotland. The main focus with the project was to help children with physical disabilities to create spoken words by blending sounds together on the PhonicStick. It was also hypothesized that the PhonicStick could act as a support to literacy learning with typically developing children.</p><p>The aim of the present study was to investigate if a group of 10 typically developing South African 5-6 year old children could learn how to use the PhonicStick in three sessions and to see if their phonological awareness improved by using it. The training with the PhonicStick took place over a period of three weeks. The participants’ phonological awareness was screened before and after the sessions with two sub-tests of The Phonological Awareness Test (PHAT). In addition, their ability to produce sounds and words with the PhonicStick was tested.</p><p>The results showed that all the participants appeared to be interested in the PhonicStick and that they found it relatively easy to manoeuvre. The participants’ ability to produce sounds and words on the PhonicStick showed a statistically significant improvement from the first session to the third session. The participants’ phonological awareness skills did not appear to improve after three sessions. More time is needed to find out if this training would result in improved phonological awareness skills.</p>

Literacy is an important part of communication. Phonological awareness, i.e. the ability to recognise the sound units of language and to manipulate them, has been found to be crucial in literacy acquisition. In 2005 the development of a communication device, a talking joystick called the PhonicStick, started at The School of Computing at the University of Dundee in Scotland. The main focus with the project was to help children with physical disabilities to create spoken words by blending sounds together on the PhonicStick. It was also hypothesized that the PhonicStick could act as a support to literacy learning with typically developing children. The aim of the present study was to investigate if a group of 10 typically developing South African 5-6 year old children could learn how to use the PhonicStick in three sessions and to see if their phonological awareness improved by using it. The training with the PhonicStick took place over a period of three weeks. The participants’ phonological awareness was screened before and after the sessions with two sub-tests of The Phonological Awareness Test (PHAT). In addition, their ability to produce sounds and words with the PhonicStick was tested. The results showed that all the participants appeared to be interested in the PhonicStick and that they found it relatively easy to manoeuvre. The participants’ ability to produce sounds and words on the PhonicStick showed a statistically significant improvement from the first session to the third session. The participants’ phonological awareness skills did not appear to improve after three sessions. More time is needed to find out if this training would result in improved phonological awareness skills.

The purpose of this study is to investigate the teachers’ described experiences of advantages as well as disadvantages of Arne Trageton’s write to read-method (“ASL”) in contrast to the code-oriented traditional way of teaching. The aim of this study is furthermore to depict the teachers’ opinions on whether they experience that the ASL-method is unfavourable for students in general. This study will also investigate the teachers’ standpoint regarding choice of reading and writing method. The following questions form the basis of this study: Which advantages or disadvantages do the teachers experience with the ASL-method relative to using the code-oriented traditional way of teaching? Do the teachers experience that the ASL-method is unfavourable for some students? Do the teachers only use the ASL-method or do they combine many different reading and writing methods in their teaching? How do the teachers explain their decision in that matter? This study is based on a qualitative method and interviews were performed to acquire knowledge of the teachers’ experiences. The major theoretical approaches of this study are Arne Trageton’s, the founder of the ASL-method, theories concerning the ASL-method and the socio-cultural perspective on learning. The result of the study demonstrates that the ASL-method is described as advantageous because the students’ interests, creativity, motivation and self-confidence increased when using the ASL-method, in contrast to using the traditional way of teaching. The ASL-method was also described as easier to individualize in comparison with the traditional letter-based teaching. The disadvantage with the ASL-method, in contrast to using the traditional teaching, was mainly the fact that the computers and tablets sometimes did not work properly. Overall the ASL-method was described as a good method because all students could participate in the teaching despite their capacity. Speech technology and word editing programs on the tablets were described as descent support for students with slower motor development, difficulties in reading or writing and second language students. Even though the ASL-method was considered a superior method, the method was not described to be sufficient by itself.

No description available.

No description available.

Under de senaste åren har antalet nyanlända ökat i Sverige vilket innebär en större flerspråkighet i skolan. I vår tidigare kunskapsöversikt undersöktes de två teoretiska läsmodellerna, Phonics och Whole Language, utifrån ett flerspråkigt perspektiv. I kunskapsöversikten framkom en intressant faktor som belyste vilken läsinlärningsmodell som bör användas i läsundervisningen gällande ett flerspråkigt barn. Faktorn nämnde att det beror på i vilken ålder ett flerspråkigt barn blivit exponerat för sitt andraspråk. För att lärare ska ta reda på när en elev blivit exponerad för sitt andraspråk ska hen undersöka elevens språkliga bakgrund. För att inhämta information om den flerspråkiga elevens språkliga bakgrund behöver eleverna kartläggas. Studien syftar därför till att ta reda på vilka former av kartläggning verksamma F- 3 lärare använder sig av när de kartlägger flerspråkiga elever och om lärare tar hänsyn till flerspråkiga elevers förutsättningar i val av läsmetoder. Undersökningsmetod för den insamlade empirin är enkät som innefattar både kvalitativa och kvantitativa frågor. Undersökningen resulterade i att kartläggningsformerna är mångfaldiga. De kartläggningsmetoder som framkom ur resultatet var ett kartläggningsprogram, egen kartläggning, kartläggning i samspel med resurs, att lärare tog del av resursernas kartläggning samt muntlig kartläggning. Det framgår inte om kartläggningen ligger till grund för den metod som lärare väljer i läsundervisning utan lärarna väljer den metod de själva anser gynna de flerspråkiga eleverna. Det framgår heller inte om lärare tar hänsyn till flerspråkiga elever förutsättningar i val av läsmetod.