The research reported on in this thesis forms part of the foundation of a bigger research project in which an attempt is made to provide better, faster and more efficient feedback on student writing. The introduction presents the localised and international context of the study, and discusses some of the problems experienced with feedback practice in general. The introduction also gives a preview of the intended practical implementation of the research reported on in this thesis. From there on, the thesis is presented in article form with each article investigating and answering a part of two main guiding questions. These questions are: 1. Does feedback on student writing work? 2. How can feedback on student writing be implemented as effectively as possible? The abstracts for the five individual articles are as follows: Article 1 Article 1 presents a rubric for the evaluation of Computer-Assisted Language Learning (CALL) software based on international recommendations for effective CALL. The rubric is presented after a brief overview of the pedagogical and implementation fundamentals of CALL, and a discussion of what needs to be included in a needs analysis for CALL evaluation. It is then illustrated how the evaluation criteria in the rubric can be used in the design of a new CALL system. Article 2 Providing feedback on student writing is a much-debated topic. One group of researchers argues that it is ineffective and another group remains convinced that it is effective, while at ground level teachers and lecturers simply carry on “marking” texts. The author of this article contends that both arguments have valid contributions to make and uses the arguments both for and against feedback to create a checklist for effective feedback practice. Adhering to this checklist should counter most of the arguments against feedback while supporting and improving the positive arguments in favour of feedback. Article 3 This article reports on an experiment which tested how effectively standardised feedback could be used when marking L2 student writing. The experiment was conducted using a custom-programmed software tool and a set of standardised feedback comments. The results of the experiment prove that standardised feedback can be used consistently and effectively to a degree, even though some refinements are still needed. Using standardised feedback in a standard marking environment can assist markers in raising their awareness of errors and in more accurately identifying where students lack knowledge. With some refinements, it may also be possible to speed up the marking process. Article 4 This article describes an experiment in which Boolean feedback (a kind of checklist) was used to provide feedback on the paragraph structures of first-year students in an academic literacy course. The major problems with feedback on L2 writing are introduced and it is established why a focus on paragraph structures in particular is of importance. The experiment conducted was a two-draft assignment in which three different kinds of feedback (technique A: handwritten comments; technique B: consciousness raising through generalised Boolean feedback; and technique C: specific Boolean feedback) were presented to three different groups of students. The results indicate that specific Boolean feedback is more effective than the other two techniques, partly because a higher proportion of the instances of negative feedback on the first draft were corrected in the second draft (improvements), but more importantly because in the revision a much lower number of changes to the text resulted in negative feedback on the second draft (regressions). For non-specific feedback, almost as many regressions occurred as improvements. In combination with automatic analytical techniques made possible with software, the results from this study make a case for using such checklists to give feedback on student writing. Article 5 This article describes an experiment in which a series of statements, answerable simply with yes or no (labelled Boolean feedback), were used to provide feedback on the introductions, conclusions and paragraph structures of student texts. A write-rewrite assignment (the same structure as in article 4) was used and the quality of the student revisions was evaluated. The results indicate that the students who received Boolean feedback showed greater improvement and fewer regressions than students who received feedback using the traditional method. The conclusion provides a brief summary as well as a preview of the immense future research possibilities made possible by this project. / Thesis (Ph.D. (English))--North-West University, Potchefstroom Campus, 2011.

The StringToStringCorrection problem asks, given mutable string M, target string T, and positive integer k, can M be mutated into T using at most k operations (single symbol deletions or swaps of adjacent symbols) applied to M? The problem is known to be NP-complete. Abu-Khzam et al. give the first fixed-parameter algorithm for the problem when the parameter is the number of operations permitted. Their technique, charge and reduce, gives a O^∗(1.612k) bounded search tree algorithm, but leaves open whether a poly-size kernel exists. We show, using two polynomial time reduction rules on large regions of the input strings, that the problem has a problem kernel of size O(k^4). Our algorithm achieves this in a polynomial running time. Additionally, we introduce the problem k-MultiStringToStringCorrection (k-MS2SC), a generalized version of StringToStringCorrection, and prove it to be fixed-parameter tractable. / Graduate / 0984 / nwatt@uvic.ca

This thesis discusses the chemistry and physics of Cu and H2O on ZnO surfaces, based primarily on results from quantum chemical calculations. The underlying context is heterogeneous catalysis, where Cu/ZnO-mixtures are used in the industrial synthesis of methanol and in the water gas shift reaction. Electron transfer between small Cu clusters and ZnO is central to this thesis, as are the design and use of models that can describe realistic and very large-scale ZnO surface structures while still retaining the electronic nature of the system. Method and model enhancements as well as tests and validations constitute a large part of this thesis. The thesis demonstrates that the charges of small Cu clusters, adsorbed on the non-polar ZnO(10-10) surface, depend on whether the Cu clusters contain an even or odd number of atoms, and whether water is present (water can induce electron transfer from Cu to ZnO). On the polar Zn-terminated ZnO(0001) surface, Cu becomes negatively charged, which causes it to attract positively charged subsurface defects and to wet the ZnO(0001) surface at elevated temperatures. When a Cu cluster on a ZnO surface becomes positively charged, this happens because it donates an electron to the ZnO conduction band. Hence, it is necessary to use a method which describes the ZnO band gap correctly, and we show that a hybrid density functional, which includes a fraction of Hartree-Fock exchange, fulfills this requirement. When the ZnO conduction band becomes populated by electrons from Cu, band-filling occurs, which affects the adsorption energy. The band-filling correction is presented as a means to extrapolate the calculated adsorption energy under periodic boundary conditions to the zero coverage (isolated adsorbate, infinite supercell) limit. A part of this thesis concerns the parameterization of the computationally very efficient SCC-DFTB method (density functional based tight binding with self-consistent charges), in a multi-scale modeling approach. Our findings suggest that the SCC-DFTB method satisfactorily describes the interaction between ZnO surfaces and water, as well as the stabilities of different surface reconstructions (such as triangularly and hexagonally shaped pits) at the polar ZnO(0001) and ZnO(000-1) surfaces.

Optical see-through display (OSTD) is a transparent digital display which simultaneously gives access to the digital contents and the real world objects behind it. Additive optical see-though display is a hardware subtype of OSTD which has its own light source to create the digital contents. In Additive OSTD, light coming from background objects mixes with the light originating from the display causing what is known as the color blending problem. The work in this thesis provides a solution to the color blending problem. In order to understand the problem, this thesis first presents a new color blending model for additive OSTD based on two display induced distortions: the Render distortion and the Material distortion. A new method called Binned Profile (BP) method which accounts for the render distortion is developed to predict the blended color, when applied on the color blending model. BP method is validated with other known methods and is shown to be the most accurate in predicting the color blends with 9 just noticeable differences (JND) in worst case. Based on the BP method, a new color correction algorithm called BP color correction is created to solve the color blending problem. BP-color correction finds the alternative digital color to counter balance the blending. The correction capacity of various digital colors were analysed using the BP color correction approach. BP color correction is also compared and proven to be better than the existing solution. A quicker version of the correction called quick correction is also explored. The thesis concludes with an exploration of the material distortion, explains the limitations of BP-correction, provides design recommendations .

In this work, a major effort has been made to establish an Internet accessible system for medical imaging simulation as a convenient service under the cloud computing environment. First, an Internet accessible, medical imaging education platform has been developed. It includes teaching and dynamic assessment tracking system for five commonly used imaging modalities. The system is integrated by the open source MySQL database software that manages updating materials and also tracks students’ learning engagements, which allow the reliability and appropriateness of the on-line teaching material and assessment methods to be optimized. The evaluation results have shown increased learning gains promisingly. Second, a prototype simulation service platform has been established. It is based on a job-oriented work flow to provide different kinds of service to users to perform medical imaging simulation. These simulations not only include the straightforward CT data reconstruction based on Radon transform, but also the sophisticated PET imaging simulation based on GATE as well. The QGATE’s client-server configuration can manage the GATE system to queue and monitor the submitted simulation scripts and return simulation results. The system is suitable for classroom training and easy to use for students or new users to the field of nuclear medicine imaging simulation. Finally, based on the developed simulation platform, a simulation study on PET imaging has been carried out. Event-based dynamic justification method has been tested based on the phantoms generated by NCAT associated with different breathing signals. The results show its potential capability of motion correction for PET data acquisition.

What actions constitute reasonable correction (or reasonable corporal punishment) of children pursuant to section 43 of the Criminal Code has been the subject of much legal debate in recent years. In this thesis, I argue that the Supreme Court of Canada’s analysis of section 43 in Canadian Foundation for Children, Youth and the Law v. Canada (Attorney General) (2004) failed to sufficiently delineate the justification, as demonstrated by the fact that the Court’s ruling has subsequently been manipulated and misinterpreted by lower courts across Canada. The post-Canadian Foundation jurisprudence has established a need for clarity, both with respect to the scope of section 43 and the provision’s proper application. I argue that Parliamentary reform of section 43 is required and I conclude by suggesting an amendment to the justification that seeks to incorporate current social science views on the issue and resolve the post-Canadian Foundation issues.

The purpose of the paper is to explore the relationship between inflation and unemployment in Germany during the period from 1970 to 2012. Through the methods of cointegration, dynamic OLS and an error correction model, this paper highlights that there is no short run negative relationship between inflation and unemployment, and consequently the short run Phillips curve is an unsuitable instrument for making political decisions. Furthermore, there is a long run relationship between inflation and unemployment, which can be explained with asymmetric nominal wage rigidities and resulting frictional growth. Resulting policy implications reflect the advantage of a permanent higher inflation target for Germany. Since the beginning of the European Monetary Union, Germany has been on average 0.5% under the permanent inflation target of the central bank. Therefore, by using fiscal policy, Germany can reduce permanent unemployment without missing the inflation target of the central bank. Finally, despite of variety of intensive changes in the macroeconomic situation and particularly through the establishment of the European Monetary Union, the CUSUM and CUSUMsq test reveal that the estimate holds validity over the entire observation period and has not changed since the beginning of the European Monetary Union.

Revision of Thesis (doctoral)--University of Helsinki, 1978. / Includes indexes. Includes bibliographical references (p. 109-112).

The development of a quantum computer presents one of the greatest challenges in science and engineering to date. The promise of more efficient computing based on entangled quantum states and the superposition principle has led to a worldwide explosion of interest in the fields of quantum information and computation. Among the number of hurdles which must first be cleared before we witness a physical realization are problems associated with environment-induced decoherence and noise more generally. However, the discovery of quantum error correction and the establishment of the accuracy threshold theorem provide us with the hope of someday harnessing the potential power a functioning fault-tolerant quantum information processor has to offer. This dissertation contributes to this effort by investigating a particular class of quantum error correcting codes, namely noiseless subsystem encodings. The passive approach to error correction taken by these encodings provides an efficient means of protection from symmetrically coupled system-environment interactions. Here I will present methods for determining the subsystem-preserving evolutions for noiseless subsystem encodings supported by arbitrary-dimensional physical quantum systems. Implications for universal, collective decoherence-free quantum computation using the derived operations are discussed. Moreover, I will present a proposal for an optical device which is capable of preparing a variety of these noiseless subsystem encodings through a postselection strategy.

L’introduction en clinique de la bimodalité combinant la tomographie d’émission de positons (TEP) et la tomodensitométrie (TDM) a été un succès dans les années 2000. La multimodalité dans le contexte de l’imagerie médicale a souvent pour but de combiner une information physiologique à une information anatomique. Deux approches existent : la première étant d’acquérir séparément les modalités et de les combiner ultérieurement par fusion d’images sur ordinateur, la seconde s’affranchit des problèmes possibles du recalage en opérant une acquisition dans le même statif des deux modalités. Cependant, il existe des limites à l’imagerie TEP/TDM. L’idée de combiner l’imagerie par résonance (IRM) magnétique à la TEP offre des avantages par rapport à la TDM. Notamment, l’IRM offre un excellent contraste des tissus et offre l’accès à de l’information multidimensionnelle, fonctionnelle et morphologique grâce à la modularité offerte par l’acquisition IRM. Cette information pourrait permettre de mieux comprendre les processus physiopathologiques des maladies. De plus, l’IRM n’est pas ionisante, au contraire de l’imagerie TDM. L’introduction au début des années 2010 des premiers appareils d’acquisition simultanée TEP/IRM offre de nombreuses possibilités, mais il reste des défis à résoudre avant d’assister à la même diffusion en clinique que l’imagerie TEP/TDM de ces appareils. Notamment, l’atténuation photonique, qui doit être corrigée afin de permettre le caractère quantitatif de l’imagerie, est un problème. Dans ce travail, nous abordons cette question en proposant des solutions pour les différentes régions du corps. Une attention particulière est portée à la région pelvienne. L’état de l’art des méthodes disponibles expose un faible nombre de solutions pour cette région, pourtant riche en tissus osseux atténuants et zone d’occurrence du second cancer le plus commun chez l’homme : le cancer de la prostate. Nous évaluons l’impact de la solution proposée sur la correction des photons diffusés, toujours dans un objectif d’obtenir une imagerie quantitative. Les différentes méthodologies de correction et d’évaluation font intervenir des simulations numériques Monte Carlo. / The clinical introduction of the bimodality combining the positron emission tomography (PET) and the computed tomography (CT) has been a major success in the 2000s. Multimodality, in the context of medical imaging, often has the aim of associating a physiological information and an anatomical information. Two approaches exist : either the two modalities are acquired separately and then fused through computerized image fusion, or we discard the issues related to image registration by acquiring in the same system the two modalities. However, there remain limits to PET/CT imaging. The idea to combinemagnetic resonance imaging (MRI) to PET offers solutions and advantages compared to the use of TDM.MRI offers an excellent tissue contrast and offers an access to multidimensional functional and morphological information thanks to the modularity offered by MRI. This information could improve the understanding of the physiopathological processes involved in diseases. Moreover, MRI is non-ionizing modality, on the contrary to CT. The introduction in the early 2010s of the first simultaneous PET/MRI systems offers a lot of possibilities, but there remains challenged to solve before observing the same spread as the PET/CT in imaging facilities. In particular, the photon attenuation, which must be corrected to provide a quantitative imaging, remains an issue. In this work, we address this issue by proposing solutions for the different regions of the body. A special attention is drawn to the pelvic region. Indeed, the state of the art of available methods exposes a small number of solutions for this area ; even so it is rich in attenuation osseous tissues et area of occurrence of the second most common cancer in men : prostate cancer. We assess the impact of the proposed solution on the scattered photons correction, still in the aim of obtaining a quantitative imaging modality. The different methodologiesof correction and evaluation use Monte Carlo numerical simulations.