A multi-pass one way method to include turning waves and multiples

Conventional one way migration methods exclude turning waves and multiples. We propose an algorithm that uses multiple passes to extend the one way method to efficiently include these wavepaths. A comparison of the images produced by the regular one way algorithm, RTM, and the new method, shows that this new method can significantly improve the image in regions of interest, and in certain situations may even provide more useful information than RTM. The runtime is demonstrated to be in between that of regular one way and RTM, while the physical memory required is considerably lower than that of RTM

Reverse Time Migration in the presence of known sharp interfaces

We propose using the forward propagated source wave to create synthetic receiver data on the surfaces of the computational domain where real receiver data is not available as a means of exploiting known information about reflector locations in Reverse Time Migration. The inclusion of synthetic boundary data can make true amplitude imaging possible, and reduce the artifacts associated with the inclusion of multiples. Here, we describe the new method, present synthetic examples, and propose an appropriate imaging condition

Feedback on Academic Essay Writing through pre-Emptive Hints: Moving Towards "Advice for Action"

This paper adopts an “advice for action” approach to feedback in educational practice: addressing how provision of “hints” to participants before they write academic essays can support their understanding and performance in essay-writing tasks. We explored differences in performance by type of hint, and whether there was a transfer of better performance in subsequent essays. Fifty participants were recruited, consisting of eight men and 42 women aged 18-80. Participants were assigned in rotation to four groups, and asked to write two essays. Groups 1 and 3 received hints before Essay 1, whilst Groups 2 and 4 received hints before Essay 2. Groups 1 and 2 received essential hints; Groups 3 and 4 received helpful hints. Essays were marked against set criteria. The results showed that an “advice for action” approach to essay-writing, in the form of hints, can significantly improve writers’ marks. Specifically higher marks were gained for the introduction, conclusion and use of evidence: critical components of “good” academic essays. As the hints given were content-free, this approach has the potential to instantly benefit tutors and students across subject domains and institutions and is informing the development of a technical system that can offer formative feedback as students draft essays

Exploring the relation between cigarette smoking and alcohol hangover frequency

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on November 5, 2007)Includes bibliographical references.Thesis (M.A.) University of Missouri-Columbia 2007.Dissertations, Academic -- University of Missouri--Columbia -- Psychology.Drinkers differ meaningfully in their susceptibility to hangover, and prior studies suggest individual differences in hangover proneness may be related to risk for alcohol use disorders (AUD). This project examined whether smoking behavior, a frequent concomitant of drinking, accounts for some of the variation in self-reported hangover. Data from a longitudinal familial high-risk study (N=489; 51% with a family history of AUD) were used to assess the association of smoking with hangover. Cross-sectional and multilevel regression results revealed a main effect for smoking such that smokers reported higher mean hangover, and smoking interacted with alcohol consumption such that the relation between drinking and hangover was weaker among smokers than among nonsmokers. Exploration of hangover at early and late time-points among naturally occurring groups who changed smoking status reinforced these results. Logistic regression analyses showed that hangover was associated with risk for AUD, and that this effect remained even after controlling for smoking status, suggesting the relation between early hangover and later AUD is not simply an artifact of failing to account for smoking behavior. These findings raise the intriguing possibility that smoking contributes to individual variation in hangover, and that smoking might be a permissive factor in the escalation of drinking

OpenEssayist: real-life testing of an automated feedback system for draft essay writing

OpenEssayist is unique in being an automated feedback system that has been developed to offer feedback on students' draft essays, rather than assessment on their finished work. This is therefore a system that offers opportunities for students to engage with and reflect on their work, and to improve their work through understanding of the requirements of academic essay writing. In trialling use of the system in a genuine Open University course, we found that students made use of it to varying degrees, which is perhaps likely with any study resource. Those who took the time to explore system affordances and what they could be used for however tended to report more positively on its perceived value. From our analysis we were also able to conclude that a significant positive correlation exists in this sample of students between marks on essay 1 and the number of drafts submitted. We could speculate as to what this may mean for this set of students, or more widely, but it seems clear that use of a system such as OpenEssayist has many potential advantages to students and tutors, which will benefit from further research and exploration

What types of essay feedback influence implementation: Structure alone or structure and content?

Students approach educational courses with varying levels of experience and understanding, and so need appropriate support to inform them of expectations and to guide their learning efforts. Feedback is critical in this process, so that learners can gauge how their performance aligns with expectations, and how they can improve their efforts and attainments. This study focused on the effects of providing different types of feedback on participants’ written essays, as well as on participants’ motivations for learning using measures of motivation and self-efficacy. In terms of research questions, it was important to ascertain whether participants performed differently in subsequent essays after receiving feedback on structure alone or on structure and content; whether their self-reported levels of motivation and attitudes to learning were related to essay performance; and whether the difference in type of feedback affected their self-reported levels of motivation and attitudes to learning. Findings revealed no significant difference in marks between those receiving feedback on structure alone and those receiving feedback on structure and content, which is surprising and deserves further exploration. Even so, using feedback to highlight certain structural elements of essay writing can have a lasting positive impact on participants’ future essay performance

Cascading the use of Web 2.0 technology in secondary schools in the United Kingdom: identifying the barriers beyond pre-service training

This paper reports on research that took place at Nottingham Trent University and Sheffield Hallam University, United Kingdom, over two years. The research focuses on the use of Web 2.0 technology, specifically web logs, with pre-service teachers, both during their university programme and the first year of teaching as full-time newly qualified teachers (NQTs). The purpose of this research was to add a developing body of knowledge by identifying whether technology used by pre-service teachers during their training course can be cascaded into their practice once qualified. Key findings identify a number of enablers and barriers to cascading technology in the classroom; these include curriculum time, pupil skills and support. The research concludes that early professional support and development should be on-going and assumptions about new teachers as champions of cascading innovative use of Web 2 technologies into their practice as NQTs may be over optimisti