428 results for Conference poster

  • The Acoustic Contrasts of Emotional Expressions in New Zealand English

    Jayakody, D.; Lin, E.; Looi, V. (2010)

    Conference poster
    University of Canterbury Library

    Listeners can identify emotions based on vocal cues (Banse & Scherer, 1996). This study aims at identifying the acoustical parameters that aid in recognizing different emotions, for a better understanding of the difficulties faced by cochlear implant (CI) and hearing aid (HA)users in real life situations.

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  • Electrocochleography and Subjective Methods for the Diagnosis of Meniere’s disease

    Kalin, C.; Lin, E.; Hornibrook, J.; O’Beirne, G. (2010)

    Conference poster
    University of Canterbury Library

    between electrocochleography (ECochG) measures and the subjective scores based on the clinical guidelines provided by the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing Equilibrium (AAO-HNS CHE) and the Gibson‟s Score. A total of 250 potential MD patients who have had their MD-related signs and symptoms documented and ECochG testing completed in the Department of Otolaryngology at Christchurch Hospital were included. A selection of details obtained from both the AAO-HNS CHE and ECochG testing results were examined to allow for an investigation on the function of these methods as a diagnostic tool for MD. The inter-method reliability between ECochG and the two subjective methods for the diagnosis of MD was found to be high. In addition, patients that tested “positive”, regardless of the diagnostic method used, showed a higher correlation among the four key symptoms of MD. These results demonstrate that ECochG is an effective diagnostic tool but should not be used as the sole assessment for the diagnosis of MD. This research provides empirical evidence in support of using ECochG as an effective tool as part of the differential diagnosis of MD.

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  • Acoustic Signs of Supraglottal Constriction in Pathological Voices

    Lin, E.; Ormond, T.; Hornibrook, J.; Henderson, N. (2010)

    Conference poster
    University of Canterbury Library

    Purpose: This study aims to identify the acoustic signs of supraglottal constriction and effects of some vocal manipulation techniques. It is hypothesized that some task-related acoustic contrasts would differ between voice patients with and without supraglottal constriction due to different vocal tract configurations. Method: Classified through videostroboscopic examinations, 30 participants were gender and age-matched to form two comparison groups (“constricted” and “non-constricted”), with five males and ten females in each group. Participants were asked to sustain a vowel (/a/ or /i/) for approximately three seconds in five tasks, including normal-pitch, low-pitch, high-pitch, /m/-onset (i.e., with the consonant /m/ preceding the vowel at normal pitch), and /h/-onset tasks. Acoustic signals were analyzed to extract measures from the mid-portion of the vowel. Results: The “constricted” group showed a lack of task-related contrasts on signal-to-noise ratio, singing power ratio, frequency of the second formant, and the amplitude difference between the first formant and the first harmonic. Conclusion: Further investigations are needed to assess the predictive power of the proposed task-based acoustic approach for detecting supraglottal constriction.

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  • The suitability of iPhone recordings for the acoustic measures of speech and voice quality

    Lin, E.; Hornibrook, J. (2011)

    Conference poster
    University of Canterbury Library

    This study examined the quality of iPhone recordings for acoustic measurements of speech and voice quality. A selection of acoustic measures were extracted from voice samples recorded using the “voice memo” application in an iPhone and compared with those derived from signals directly digitized (DD) in a laptop via a 12-bit A/D converter. Participants were 11 healthy adults, including six females and five males, aged between 27 to 67 years (Mean = 41.8 years, SD = 16.7). The participant was asked to read the first six sentences of the “rainbow passage”. In addition, two participants were asked to produce sustained vowels (/i/, /a/, and /u/) and a sentence (“We saw two cars”) ten times. The simultaneously recorded iPhone and DD signals were analysed to derive 10 acoustic measures, including spectral tilt for the whole sentence and fundamental frequency (F0), percent jitter, percent shimmer, signal-to-noise ratio, amplitude of the first harmonic relative to that of the second harmonic, singing power ratio, and frequencies of the first and second formants (F1 and F2), and vowel space area for the vowel segment. A series of Pearson’s correlation procedures revealed that measures from iPhone and DD signals were highly correlated. Findings of the vowel effect on the experimental measures obtained from iPhone signals were consistent with those from DD signals. However, the mean normalized absolute differences between measures from iPhone and DD signals are optimal (i.e., lower than 20%) only for F0, F1, and F2. These findings suggest that iPhone recordings are as adequate as other types of high quality digital recordings for acoustic measurements of voice quality but most voice measures from different digital recording systems are not directly comparable.

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  • Library services without a library: post-earthquake use of virtual reference at University of Canterbury

    Roberts, S.F.; Fitchett, D.J.; Paterson, M.E. (2011)

    Conference poster
    University of Canterbury Library

    Following the September 2010 earthquake and the closure of a number of campus libraries, library staff at the University of Canterbury was forced to rethink how they connected with their users. The established virtual reference service now meant library staff could be contacted regardless of their physical location. After the February earthquake, with University library closures ranging from 3 weeks to indefinite, this service came into its own as a vital communication tool. It facilitated contact between the library and both students and academics, as well as proving invaluable as a means for library staff to locate and communicate with each other. Transcripts from our post-earthquake interactions with users were analyzed using NVivo and will be presented in poster format showing the increase in usage of the service following the earthquakes, who used the service most, and the numbers and types of questions received. Our virtual reference tool was well used in the difficult post-earthquake periods and we can see this usage continuing as university life returns to normal.

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  • Bacterial Contamination Assessment of Rural Ugandan Drinking Water Sources Using EC 3M TM petrifilms TM

    Pearson, A.L.; Long, V.; Meschke, J.S.; Roberts, M.C.; Mayer, J.D. (2007)

    Conference poster
    University of Canterbury Library

    This study examined bacterial contamination levels from 47drinking water sources(92%were surface sources)from two rural Ugandan villages using EC 3M TM petrifilmsTM incubated for 24 h at 37ºC. E. coli counts in 1ml water samples ranged from 0-120 cfu/ml. Confirmation of presumptive E. coli was performed by transferring colonies onto Blood agar followed by characterization by subculture on selective media and standard biochemical analysis. Selected isolates were verified by sequencing of their 16S rRNA genes. A total of 184 colonies were isolated from petrifilms representing 70%of the water sources and 92% of the isolates were identified to genusl evel (n=169). Only 24%of presumptive E. coli, isolates were confirmed as E. coli (n=40). Additionally 61%of isolates were found to be lactose negative and were confirmed as Salmonella, Yersinia and Proteus (n=103). Purified bacterial isolates from the Ugandan water samples and laboratory strains were replated on new petrifilms at various dilutions to determine the potential for misclassification of colony color or gas production. Upon inoculation of new petrifilms, misclassification of coliforms was observed. While the level of bacterial contamination in the rural Ugandan drinking water sources is not unexpected, isolation of lactose negative bacteria from presumptive E. coli colonies and misclassification of coliforms by the petrifilms was unexpected.

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  • Effects on Motor Vehicle Behavior of Color and Width of Bicycle Facilities at Signalized Intersections

    Mangundu, E.; Koorey, Glen (2010)

    Conference poster
    University of Canterbury Library

    Research was undertaken in Christchurch, New Zealand to investigate motor vehicle behavior near bicycle facilities at signalized intersections. Motorists not keeping clear of such facilities may limit their usefulness and safety for bicyclists. The main research objective was to assess motorists’ avoidance of colored facilities in comparison to uncolored ones. The research also investigated if wide combined bicycle and traffic lanes encourage drivers to queue side-by-side, thereby encroaching into bicyclist spaces. 18 sites were identified to evaluate the effect of colored surfacing and lane widths on the rate at which motorists encroach on marked bicycle spaces. The sites contained either Advanced Stop Lines (ASL) or Advanced Stop Boxes (ASB) and were a mix of colored and uncolored facilities with “narrow” and “wide” lane combinations. Manual surveys were carried out to observe the positions of motor vehicles in relation to the bicycle facilities. Four of the uncolored sites were then colored and “after” surveys conducted. The results showed that drivers were much less likely to encroach on colored bicycle spaces in comparison to uncolored ones, particularly ASLs. Motorists were also more likely to encroach on bicycle lanes in “wide” lane combinations. It is recommended that road agencies continue coloring new and existing bicycle facilities at intersections, with preference given to existing ASLs over ASBs and sites with wider approaches. Traffic and bicycle lane combinations greater than 5.0 m (16½ ft) should also be avoided if separate turning traffic lanes are not present.

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  • Investigating and Modelling the Effects of Traffic Calming Devices

    Mao, J.; Koorey, Glen (2010)

    Conference poster
    University of Canterbury Library

    This research investigated the effects on traffic volumes, speeds and crashes of traffic calming devices on urban local streets. Eleven sites in Christchurch with street calming devices were evaluated using field surveys and network modelling using TrafikPlan, and compared with findings from a literature review. The main findings of the studies were: at seven sites that used vertical devices for treatment, five of them had reduced traffic volumes and speeds; at ten sites that used horizontal devices, eight of them had experienced reductions in volumes and speeds; from the crash history, it was found that road safety has been noticeably improved after installation of the traffic calming devices, with average crash reductions of 15-20%; in terms of network performance, TrafikPlan modelling seems promising for estimating traffic volume and speed changes on treated local streets and adjacent arterial roads. This paper will discuss these findings and speculate on how the devices investigated affect traffic behaviour. It is recommended that further research be conducted at more sites and for longer time periods to build up a comprehensive local database of traffic calming treatments. Future studies should also investigate the effectiveness of environment impacts of the devices, i.e. noise and air pollution.

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  • Distributions of gene tree branch lengths under coalescence

    Degnan, J.; Kubatko, L. (2008)

    Conference poster
    University of Canterbury Library

    In Bayesian phylogenetic inference, commonly used prior distributions for branch lengths are the uniform, exponential, and gamma distributions. We derive the exact distributions of branch lengths of gene trees under a fixed species tree using the coalescent model. We find that the distributions of branch lengths depend on both the shape and branch lengths of the species tree, which depend on the population genetic parameters of ancestral population sizes and divergence times. Distributions of branch lengths are formed by mixtures depending on the ancestral populations in which coalescent events occur (coalescent histories). For some sets of moderately short branches, these mixtures can lead to distributions of branch lengths which are not well approximated by uniform, exponential, or gamma distributions, thus suggesting that a prior based on a mixture of distributions might be more appropriate for inferring branch lengths on some gene trees.

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  • Calibration of Overseas Highway Crash Prediction Models for New Zealand - a Case Study with IHSDM

    Koorey, Glen (2010)

    Conference poster
    University of Canterbury Library

    Crash prediction models (CPMs) are an increasing feature of rural highway design practice internationally. A significant related development was the Interactive Highway Safety Design Model (IHSDM) in the US. However it would be difficult for every country to develop similar design tools with the same degree of complexity and research. Research has recently been exploring ways to assess the safety performance of rural highways in New Zealand. IHSDM was identified as worthy of further investigation, and a number of tasks were undertaken to adapt it for use in NZ. These included developing suitable data importing routines and calibrating IHSDM's CPM to match NZ crash patterns. A series of validation tests assessed IHSDM's effectiveness in predicting the relative safety of NZ rural roads. These included a “before and after” crash comparison of a major highway realignment, and checks of crash numbers along highway lengths in varying terrain. The investigations showed that IHSDM is a promising tool for safety and operational assessment of highway alignments (both existing and proposed) in NZ. However, IHSDM’s current lack of consideration for bridges and inconsistent road elements limit the ability of its CPM to assess sub-standard existing routes with as much accuracy as well-designed newer alignments.

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  • A 2 parameter model of lung mechanics to predict volume response and optimise ventilator therapy in ARDS

    Sundaresan, A.; Hann, C.E.; Chase, J.G.; Yuta, T.; Shaw, G.M. (2009)

    Conference poster
    University of Canterbury Library

    A majority of patients admitted to the Intensive Care Unit (ICU) require some form of respiratory support. In the case of Acute Respiratory Distress Syndrome (ARDS), the patient often requires full intervention from a mechanical ventilator. ARDS is also associated with mortality rates as high as 70%. Despite many recent studies on ventilator treatment of the disease, there are no well established methods to determine the optimal Positive End expiratory Pressure (PEEP) ventilator setting for individual patients [1]. A model of fundamental lung mechanics is developed based on capturing the recruitment status of lung units. The model produces good correlation with clinical data, and is clinically applicable due to the minimal number of patient specific parameters to identify. The ability to use this identified patient specific model to optimize ventilator management and lung volume recruitment is demonstrated. It thus provides a platform for continuous monitoring of lung unit recruitment and capability for a patient.

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  • Sub-surface Expression of Sand Volcanoes in the Avon-Heathcote Estuary Induced by the Darfield Earthquake; Analog for Sedimentary Structures in the Rock Record

    Reid, C.M.; McCombe, J.Q.; Thompson, N.K.; Laird, T.E.; Irvine, J.R.M. (2010)

    Conference poster
    University of Canterbury Library

    Among the deformation features produced in Christchurch by the September 4th Darfield Earthquake were numerous and widespread “sand volcanoes”. Most of these structures occurred in urban settings and “erupted” through a hardened surface of concrete or tarseal, or soil. Sand volcanoes were also widespread in the Avon‐ Heathcote Estuary and offered an excellent opportunity to readily examine shallow subsurface profiles and as such the potential appearance of such structures in the rock record.

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  • The application of system dynamics in power generation planning

    Jalal, T.S.; Bodger, P. (2009)

    Conference poster
    University of Canterbury Library

    Background & Introduction: The introduction of power markets in the electric supply industries (ESI) has called for a different approach to system planning and expansion. The traditional monopolistic vertically integrated system has been replaced by competing companies in the generation and retail sectors. Some of the effects on the generation planning process are: Uncertainties are increased since a department that coordinates a national planning ceases to exist Companies are no longer obligated to have generation surplus as the ESI become profit oriented Limited information is disclosed by competing companies, creating imperfect foresight on investments Non-technical factors such as market conditions, economics and social aspects are becoming more significant in building new power plants Based on these impacts, it is difficult for the power generators to decide when to invest in new power plants. Each country has its own unique environment that makes it difficult to simply adopt measures done in other countries. Hence, this study proposes to study the impact of deregulation on power generation capacity growth in New Zealand investigate suitable national policies that will ensure the reliability of the industry

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  • Temporal and spatial build-up of heavy metal contaminants in car parks

    Cochrane, T.A.; Wicke, D.; O'Sullivan, A.D. (2010)

    Conference poster
    University of Canterbury Library

    An innovative experimental system was developed to quantify contaminant loads, determine their temporal and spatial variability, and obtain large data sets required for developing contaminant build-up and wash-off stormwater modeling functions for car parks.

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  • A generalized conditional intensity measure approach and holistic ground motion selection

    Bradley, B.A. (2010)

    Conference poster
    University of Canterbury Library

    The rigorous selection of ground motions is an important consideration in a seismic risk assessment as it provides the link between seismic hazard (seismology) and seismic response (earthquake engineering). Despite the fact that many studies have highlighted the differences between the uniform hazard spectrum (UHS) and individual earthquake scenarios, the UHS is still the primary method by which ground motion records are selected and scaled. The conditional mean spectrum (CMS) is one alternative to the UHS for ground motion selection which provides the mean response spectral ordinates conditioned on the occurrence of a specific value of a single spectral period, and is directly linked to probabilistic seismic hazard analysis (PSHA). There are however several limitations in the use of the CMS for ground motion selection, which primarily stem from the fact that spectral accelerations provide only a partial picture of the true character of a ground motion. Based on the identified limitations of the CMS the objective of this work was to develop what is referred to as a generalised conditional intensity measure (GCIM) approach, which allows for the construction of the conditional distribution of any ground motion intensity measure. A holistic method of ground motion selection was also developed based on the comparison of the empirical distribution of a ground motion suite and the GCIM distributions.

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  • Rescuing concatenation with maximum likelihood using supermatrix rooted triples

    DeGiorgio, M.; Degnan, J.H. (2009)

    Conference poster
    University of Canterbury Library

    Concatenated alignments are often used to infer species-level reslationships. Previous studies have shown that analysis of concatenated alignments using maximum likelihood (ML) can produce misleading results. We develop a polynomial-time method that constructs a species tree through inferred rooted triples from concatenated alignments. We call this method SuperMatrix Rooted Triple (SMRT). We show that SMRT performs well in simulations and then show that it is a statistically consistent estimator of a clocklike species tree under a binary substitution model as well as other assumptions. SMRT is therefore a computationally efficient and statistically consistent estimator of species trees.

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  • Reference data for the LARSP profile chart for 2- and 3-year-old children

    Klee, T.; Gavin, W.J. (2010)

    Conference poster
    University of Canterbury Library

    Rationale: LARSP was one of the first clinical procedures for developmentally profiling children’s use of grammatical constructions in language samples, but its usefulness is constrained by the lack of normative data. The purpose of this study was to develop a preliminary set of norms for LARSP based on empirical data. Methods: The cross-sectional database consisted of conversational samples of 152 children from the US and UK between 24 and 48 months of age (50% girls). Twenty-minute audio recordings were made of parent-child interactions involving play with toys. Transcription and grammatical coding were done blindly (without knowledge of the child’s age or developmental status); grammatical analysis was based on standard LARSP procedures. Results: Descriptive statistics (M, SD, 95% CI) for each grammatical category on the profile chart are presented, in addition to the age at which constructions were used by 10%, 25%, 50%, 75% and 90% of the children. Conclusions: The clinical uses and limitations of the data-based profile chart are discussed as is future development of the database. Funding Source: Nuffield Foundation (UK)

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  • The effects of forest edges on dung beetle communities in a tropical montane forest

    Barnes, A.D.; Emberson, R.M.; Chapman, H.M.; Didham, R.K. (2010)

    Conference poster
    University of Canterbury Library

    Land use has been implicated as the largest global driver of biodiversity loss, largely due to associated habitat loss and fragmentation. The resulting production of habitated ges have pervasive impacts on the distribution and persistence of invertebrates. Land use change is of particular concern in African tropical montane forests as populations are increasing dramatically throughout these areas. Therefore, this study focuses on the impacts of livestock and fire on forest edges around a unique Afromontane forest in Nigeria.

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  • The influence of co-worker relationships on person-organisation misfit.

    Cooper-Thomas, H.D.; Wright, S. (2010)

    Conference poster
    University of Canterbury Library

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  • Generation of Micro-Droplets for the Study of Droplet Coalescence and Self-propulsion

    Nock, V.; Sellier, M.; Alkaisi, M.M, Verdier, C. (2011)

    Conference poster
    University of Canterbury Library

    Microfluidic devices play an ever increasing role in nano- and biotechnologies. An example of the recent breakthrough allowed by such technologies is the Lab-on-a- Chip (LOC), which enables orders of magnitude downsizing of assay equipment. An emerging area of research in this technology-driven field is digital microfluidics based upon the micromanipulation of discrete droplets. Microfluidic processing is performed on unit-sized packets of fluid which are transported, stored, mixed, reacted, or analysed in a discrete manner. Possible applications include on-chip assays, polymerase chain reaction, or DNA sequencing.

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