430 results for Conference poster

  • Identifying music documents in a collection of images

    Bainbridge, D.; Bell, T. (2006)

    Conference poster
    University of Canterbury Library

    Digital libraries and search engines are now well-equipped to find images of documents based on queries. Many images of music scores are now available, often mixed up with textual documents and images. For example, using the Google “images” search feature, a search for “Beethoven” will return a number of scores and manuscripts as well as pictures of the composer. In this paper we report on an investigation into methods to mechanically determine if a particular document is indeed a score, so that the user can specify that only musical scores should be returned. The goal is to find a minimal set of features that can be used as a quick test that will be applied to large numbers of documents. A variety of filters were considered, and two promising ones (run-length ratios and Hough transform) were evaluated. We found that a method based around run-lengths in vertical scans (RL) that out-performs a comparable algorithm using the Hough transform (HT). On a test set of 1030 images, RL achieved recall and precision of 97.8% and 88.4% respectively while HT achieved 97.8% and 73.5%. In terms of processor time, RL was more than five times as fast as HT.

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  • Earthquakes, Trees, and the 'New Normal'

    Morgenroth, J. (2011)

    Conference poster
    University of Canterbury Library

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  • Evaluating a Temporal Behaviour for Web Browsers' Back and Forward Buttons

    Cockburn, A.; McKenzie, B.; JasonSmith, M. (2002)

    Conference poster
    University of Canterbury Library

    This paper describes the evaluation of a ‘temporal’ alternative to the normal ‘stack-based’ behaviour of the Back and Forward buttons on web browsers. The main difference of the temporal scheme is that it maintains a complete list of previously visited pages. Results confirmed our prediction that the major limitation of the temporal system is in returning to parent pages. They also showed that the temporal scheme allowed many users to solve complex navigation tasks more efficiently than the stack system. Overall, the results are positive and indicate that the temporal scheme can be adapted to improve web navigation.

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  • Acoustic Analysis in Foreign Accent Syndrome: A Case Study

    Walker, J.; Lin, E. (2006)

    Conference poster
    University of Canterbury Library

    Abstract 1481/Poster Board 174

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  • The impact of breathiness on the intelligibility of speech

    Thompson, L.; Lin, E.; Robb, M.P. (2011)

    Conference poster
    University of Canterbury Library

    The aim of this study is to determine how deterioration of voice quality, such as breathiness, may impact on the intelligibility of speech. Acoustic analysis was conducted on sustained vowel phonation as well as discrete segments taken from recorded sentences, retrieved from a database of voice disordered speakers. Measures included: frequency of the first two formants (F1, F2), singing power ratio, the amplitude difference between the first two harmonics (H1-H2 amplitude difference), voice onset time, and energy ratio between consonant and vowel (CV ratio). A series of two-way (glottal closure x vowel) repeated measures Analysis of Variances conducted on these acoustic measures showed a significant glottal closure (complete vs. incomplete) or glottal closure by vowel interaction effect for the F2 frequency, H1-H2 amplitude difference, and singing power ratio. Based on findings in literature that reported a dominant first harmonic as a useful predictor of breathiness, the measure of H1-H2 amplitude difference was selected as a factor for investigation of the impact of voice quality on the perception of vowel intelligibility and clarity. Fixed-length vowel segments at five levels of H1-H2 amplitude difference were presented to 10 male and 10 female inexperienced listeners between the ages of 19 and 34 years. It was expected that the tokens with a dominant first harmonic, indicative of a more breathy voice, would be associated with a lower rate of correct vowel identification and a lower rate of being perceived as “clearer”. The finding of a change of the perceptual ratings as a function of the H1-H2 amplitude difference will demonstrate the effect of voice quality on vowel intelligibility.

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  • Simulation of site amplification effects at Heathcote Valley during the 2010-2011 Canterbury earthquakes

    Jeong, Seokho; Bradley, Brendon (2016)

    Conference poster
    University of Canterbury Library

    Heathcote Valley school strong motion station (HVSC) consistently recorded ground motions with higher intensities than nearby stations during the 2010-2011 Canterbury earthquakes. For example, as shown in Figure 1, for the 22 February 2011 Christchurch earthquake, peak ground acceleration at HVSC reached 1.4 g (horizontal) and 2 g (vertical), the largest ever recorded in New Zealand. Strong amplification of ground motions is expected at Heathcote Valley due to: 1) the high impedance contrast at the soil-rock interface, and 2) the interference of incident and surface waves within the valley. However, both conventional empirical ground motion prediction equations (GMPE) and the physics-based large scale ground motions simulations (with empirical site response) are ineffective in predicting such amplification due to their respective inherent limitations.

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  • Otolith morphometric analysis to discriminate populations of the New Zealand whitebait species Galaxias maculatus (inanga)

    Egan, E.M.; Hickford, M.J.H.; Quinn, J.M.; Schiel, D.R. (2014)

    Conference poster
    University of Canterbury Library

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  • Hybrid broadband simulations of the 2010-2011 Canterbury earthquakes

    Razafindrakoto, H.N.T.; Bradley, B.A.; Thomson, E.M.; Graves, R.W. (2015)

    Conference poster
    University of Canterbury Library

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  • Restoring the Townsend Telescope

    Pollard, K.R.; Kershaw, G.; Mullen, S.; Kershaw, D. (2015)

    Conference poster
    University of Canterbury Library

    The Townsend Observatory is located in the Arts Centre of Christchurch, in what used to be Canterbury College (now University of Canterbury). The Townsend telescope itself is a historic 6-inch Cooke refractor built in 1864 for early Christchurch colonist, Mr James Townsend, and gifted by him to Christchurch College in 1891. At the same time, the Canterbury Astronomical Society handed over its funds to the College to help erect an observatory. The College used this, and money it had set aside for a medical school, to build a biological laboratory with an attached observatory tower, which was completed in 1896. The Biology Building and Observatory Tower was the last major design by architect Benjamin Mountfort. Mr Walter Kitson was appointed custodian of the telescope and regular public open nights commenced. and continued until 2010, with the telescope being operated by students of the Department of Physics and Astronomy, University of Canterbury. The Observatory Tower was badly damaged in the 4 September 2010 earthquake and collapsed in the 22 February 2011 earthquake. The telescope was badly damaged by the collapse, but, amazingly, the optics were found entirely intact. The Department of Physics and Astronomy plans to restore the Townsend Telescope so that it can be returned to a replica Observatory Tower in its central city home, enabling the people of Christchurch, and visitors, to enjoy views of the night sky through this beautiful and historic telescope once again.

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  • An eigen-analysis of the relationships between model structure, discrete data, measurement error and resulting parameter identification distributions

    Mansell, E.J.; Docherty, P.D.; Chase, J.G.; Benyo, B. (2015)

    Conference poster
    University of Canterbury Library

    Practical rather than structural identifiability is often the determining factor whether effective parameter identification is possible in a physiological model. This paper presents analysis into relationships between the population outcomes, and the original model and data properties as part of ongoing research into a deterministic approach to evaluate a-priori identifiability. Data size, output noise variance and true parameter values were varied for a simple 2-parameter model with a linear regression equation Ax = b for discrete data points. Principal Component Analysis of a Monte Carlo simulation was compared to these varied properties and the eigendecomposition of ATA. Principal component vectors were found to be parallel with ATA eigenvectors and the eigenvalues were inversely related. Principal component eigenvalues decreased in inverse proportion to data size, were scaled by the sum of squared parameter values and noise variance. ATA eigenvalues on the other hand were unchanged by output noise and parameter value, but increased in linear, rather than inverse proportion, to data size. The ratio of principal component eigenvalues to each other was affected by data size and some parameter values, while the ATA eigenvalue ratio was affected by data size only. Deterministic relationships have been found between population parameter identification outcomes, model properties and data. If all of the factors determining principle components can be calculated then population variance can be estimated from a single set of data, facilitating confidence of individual outcomes and evaluation of practical identifiability.

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  • The precision of identified variables with respect to multivariable set size in glycaemic data from a virtual type 1 diabetic patient

    Mansell, E.J.; Docherty, P.D.; Chase, J.G. (2015)

    Conference poster
    University of Canterbury Library

    Prior research had been carried out to identify a large number of glycaemic variables in sparse, noisy data from a virtual diabetic patient. This paper investigates the precision of variables as an identification scheme introduces progressively more parameters into the variable set and as the quantity of data increases. Virtual data was simulated with a diabetic glycaemic meal model that contained six variable parameters. Data was sampled 6 times daily with noise. Increasing variable sets were identified for data subsets of increasing size. Norm-error of equivalent variable groups was compared before and after new parameter introductions. A Monte Carlo analysis was carried out to evaluate a population of results. Identifying new variables improved parameter estimates in all equivalent variable groups by 34 days in the mean population case. However, variability from data noise resulted in some cases never yielding sixparameter identification that improved upon results that relied on a-priori information. When parameters were introduced as variables too soon for the given data quality/quantity, reduced practical identifiability caused interference between these and other variables, diminishing their precision. However, when introduced too late the precision in the variable set was hindered by effects not fully described by the apriori guesses. Introducing the 3rd and 4th variables early in the data produced significant benefit in most cases. In contrast, the 5th and 6th parameters could not be introduced as early, improved precision by a lesser degree on average and in many cases never improved precision. The influence of noise on practical identifiability highlighted the need for similar analyses in-vivo so as to strategise parameter identification to gain the most information at the highest precision.

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  • Application of a meta-analysis of aortic geometry to the generation of a compliant phantom for use in particle image velocimetry experimentation

    Huetter, L.; Geoghegan, P.H.; Docherty, P.D.; Lazarjan, M.S.; Clucas, D.; Jermy, M.C. (2015)

    Conference poster
    University of Canterbury Library

    The evolution of pressure-flow geometry in the aortic arch is increasingly understood as a key element in the treatment of hemodynamic dysfunction in patients. However, little is known about the properties of the flow across the aortic geometry and thus the sensitivity of sensor placement is also unknown. Compliant models of the aortic path can be built to allow techniques such as particle image velocimetry to measure the velocity fields. This paper presents the justification and production methodology used to generate a compliant model of the aortic arch that represents the geometry and compliance of typical hemodynamics patients. The information from twenty papers was synthesized to generate a single model of the aortic arch. The model incorporates the three branching arteries at an apex of a tapering aortic path experimental that has been manufactured as a flexible thin-walled silicon model. Calculations were undertaken to ensure that the model matches the in vivo compliance of the arteries. The experimental setup uses the compliant silicone model of the aorta with variable flow pump to mimic the cardiac cycle, and a variable extramural pressure to mimic changes in intrathoracic pressure. This research was necessary for the development of an accurate experimental setup that would enable results that are immediately applicable to the research of cardiovascular therapy optimization.

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  • Identifying pressure dependent elastance in lung mechanics with reduced influence of unmodelled effects

    Laufer, B.; Docherty, P.D.; Chiew, Y.S.; Moeller, K.; Chase, J.G. (2015)

    Conference poster
    University of Canterbury Library

    The selection of optimal positive end expiratory pressure (PEEP) levels during ventilation therapy of patients with ARDS (acute respiratory distress syndrome) remains a problem for clinicians. One particular mooted strategy states that minimizing the energy transferred to the lung by mechanical ventilation could potentially be used to determine the optimal PEEP level. This minimization could potentially be undertaken by finding the minimum range of dynamic elastance. In this study, we compare an adapted Gauss-Newton method with the typical gauss newton method in terms of the level of agreement obtained in elastance-pressure curves across different PEEP levels in 10 patients. The Gauss-Newton adaptation effectively ignored characteristics in the data that are un-modelled. The adapted method successfully determined regions of the data that were un-modelled, as expected. In ignoring this un-modelled behavior, the adapted method captured the desired elastance-pressure curves with more consistency than the typical least-squares Gauss Newton method.

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  • Liquefaction triggering of Christchurch sandy soils during earthquakes

    Taylor, M.L.; Cubrinovski, M; Bradley, B.A (2015)

    Conference poster
    University of Canterbury Library

    The empirical liquefaction triggering chart of Idriss and Boulanger (2008) is compared to direct measurements of the cyclic resistance of Christchurch silty sands via undisturbed and reconstituted lab specimens. Comparisons suggest that overall there is a reasonable agreement between the empirical triggering curve and the interpreted test data. However, the influence of fines on cyclic resistance appears to be over-predicted by the empirical method, particularly for non-plastic silty sands that are commonly encountered in flood over-bank deposits in Christchurch and nearby settlements

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  • Implementation of a Non-Linear Autoregressive Model with Modified Gauss-Newton Parameter Identification to Determine Pulmonary Mechanics of Respiratory Patients that are Intermittently Resisting Ventilator Flow Patterns

    Langdon, R.; Docherty, P.D.; Chiew, Y.S.; Damanhuri, N.S.; Chase, J.G. (2015)

    Conference poster
    University of Canterbury Library

    Modelling the respiratory system of intensive care patients can enable individualized mechanical ventilation therapy and reduce ventilator induced lung injuries. However, spontaneous breathing (SB) efforts result in asynchronous pressure waveforms that mask underlying respiratory mechanics. In this study, a nonlinear auto-regressive (NARX) model was identified using a modified Gauss-Newton (GN) approach, and demonstrated on data from one SB patient. The NARX model uses three pressure dependent basis functions to capture respiratory system elastance, and contains a single resistance coefficient and positive end expiratory pressure (PEEP) coefficient. The modified GN method exponentially reduces the contribution of large residuals on the step in the coefficients at each GN iteration. This approach allows the model to effectively ignore the anomaly in the pressure waveform due to SB efforts, while successfully describing the shape of normal breathing cycles. This method has the potential to be used in the ICU to more robustly capture patient-specific behaviour, and thus enable clinicians to select optimal ventilator settings and improve patient care

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  • Equitable Evaluation of Teacher Preparation to Develop Culturally Sensitive Adaptive Expertise in Collaboration with 21st Century Networked Schools in New Zealand

    Davis, N.E.; Fickel, L. (2014)

    Conference poster
    University of Canterbury Library

    Research and evaluation of initial teacher preparation aims to inform Ministries and teacher educators worldwide on the importance of quality preparation in collaboration with schools for equitable outcomes. The New Zealand Ministry of Education is funding innovative pilot programs from 2014-2017 that will develop and research new approaches to develop teachers with adaptive expertise in networked learning environments so they respond to the needs of all learners including identified priority groups (Indigenous, Pacifika and special needs). Inclusive evaluation methodology is under development, in which the overarching approach is informed by the indigenous world views of Kaupapa Māori and seeks critical feedback. The blended online teaching that incorporates strengths-based problem solving provides both opportunities and challenges for this research.

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  • Using university level data for institutional research

    Comer, K.; Brogt, E. (2010)

    Conference poster
    University of Canterbury Library

    Background/context The university as an institution collects data on students for a variety of purposes and stakeholders, from student secondary school records to determine who will gain entrance, to student grades for academic progression and graduation, or student engagement and teaching surveys to assess the quality of education. When these data sets are combined, they can paint richer pictures of the institution, programmes of study, departments or even individual papers that would otherwise go unnoticed. Beyond that, the combined data can also inform the research on teaching and learning in tertiary settings. Analyses arising from such research can be used for professional development purposes, both to assist lecturers, departments and programmes in identifying potential issues in and across curricula and for educational managers aiming to adapt policies to improve the student learning experience. Research/evaluation method In this poster, we share examples of institutional research with combined data sets that has helped university departments develop better pictures of what types of students enter their programme, how they progress, what issues were encountered by students in the curriculum, where those issues originated and how they could be effectively addressed. In clarifying this, we will illustrate: *How using New Zealand National Certificate of Educational Achievement (NCEA) data can used to predict success in first year courses, and *How grade variability analyses (performance of the same students in different courses) can identify curricular "cake-walks" or bottlenecks. Outcomes Through illustrated examples we present both the benefits of these approaches for particular departments or lecturers, as well as the challenges in data management and the legal and ethical implications for using existing student data for research purposes. Key references American Educational Research Association. 2000, 'Ethical Standards of the American Educational Research Association,' retrieved September 7, 2007, from http://www.aera.net/uploadedFiles/About_AERA/Ethical_Standards/EthicalStandard.pdf Brogt, E., Sampson, K., Comer, K., Turnbull, M., and McIntosh, A. (in prep). NCEA achievement and success in university biology. James, A., Montelle, C., and Williams, P. (2008). From lessons to lectures: NCEA mathematics results and first-ear mathematics performance. International Journal of Mathematical Education in Science and Technology, 39(8): 1037-1050. Luan, J., and Zhao, C-M. (2006). Practicing data mining for enrollment management and beyond. New Directions for Institutional Research, 131: 117-122. Serban, A. M. (2002). Knowledge management: The 'fifth face' of institutional research. New Directions for Institutional Research, 113: 105-111.

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  • Shock Wave Lithotripsy (ESWL) results aren’t improving. What can Radiographers do to improve outcomes with better kidney stone fragmentation?

    Hayes, J.M.; Kirk, R.; Richardson, A. (2015)

    Conference poster
    University of Canterbury Library

    Findings of polymerase chain reaction (PCR) studies of cytomegalovirus (CMV) and Epstein- Barr virus (EBV) and breast cancer vary, making it difficult to determine whether either, both, or neither virus is causally associated with breast cancer. We investigated CMV and EBV in paired samples of breast cancer and normal breast tissue from 70 women using quantitative PCR. A serum sample from each woman was tested for CMV and EBV IgG. To place our results in context, we reviewed the existing literature and performed a meta-analysis of our results together with previous PCR studies of EBV, CMV, and breast cancer. Of the serology samples, 67 of 70 (96%) were EBV IgG positive and 49 of 70 (70%) were CMV IgG positive. QPCR detected EBV in 24 (34%) of the tumour and 9 (13%) of the paired normal specimens and CMV in 0 (0%) of the tumour and 2 (3%) of the paired normal specimens. Our findings, together with earlier results summarised in the meta-analysis, suggest several possibilities: variable findings may be due to limitations of molecular analyses; ‘hit and run’ oncogenesis may lead to inconsistent results; one or both viruses has a role at a later stage in breast cancer development; infection with multiple viruses increases breast cancer risk; or neither virus has a role. Future studies should focus on ways to investigate these possibilities, and should include comparisons of breast cancer tissue samples with appropriate normal tissue samples.

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  • Hybrid Broadband Ground Motion Simulations of Porters Pass Earthquakes

    Nazer, M. Ahsan; Bradley, Brendon; Razafindrakoto, Hoby (2016)

    Conference poster
    University of Canterbury Library

    We present ground motion simulations of the Porters Pass (PP) fault in the Canterbury region of New Zealand; a major active source near Christchurch city. The active segment of the PP fault has an inferred length of 82 km and a mostly strike-slip sense of movement. The PP fault slip makes up approximately 10% of the total 37 mm/yr margin-parallel plate motion and also comprises a significant proportion of the total strain budget in regional tectonics. Given that the closest segment of the fault is less than 45 km from Christchurch city, the PP fault is crucial for accurate earthquake hazard assessment for this major population centre. We have employed the hybrid simulation methodology of Graves and Pitarka (2010, 2015), which combines low (f1 Hz) frequencies into a broadband spectrum. We have used validations from three moderate magnitude events (??4.6 Sept 04, 2010; ??4.6 Nov 06, 2010; ??4.9 Apr 29, 2011) to build confidence for the ?? > 7 PP simulations. Thus far, our simulations include multiple rupture scenarios which test the impacts of hypocentre location and the finite-fault stochastic rupture representation of the source itself. In particular, we have identified the need to use location-specific 1D ??/?? models for the high frequency part of the simulations to better match observations.

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  • Characterization of dynamic soil properties and stratigraphy at Heathcote Valley, New Zealand, for simulation of 3D valley effects

    Jeong, S.; Bradley, B.A.; McGann, C.R.; DePascale, G. (2014)

    Conference poster
    University of Canterbury Library

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