Extending the task of diarization to speaker attribution

In this paper we extend the concept of speaker annotation within a single-recording, or speaker diarization, to a collection wide approach we call speaker attribution. Accordingly, speaker attribution is the task of clustering expectantly homogenous intersession clusters obtained using diarization according to common cross-recording identities. The result of attribution is a collection of spoken audio across multiple recordings attributed to speaker identities. In this paper, an attribution system is proposed using mean-only MAP adaptation of a combined-gender UBM to model clusters from a perfect diarization system, as well as a JFA-based system with session variability compensation. The normalized cross-likelihood ratio is calculated for each pair of clusters to construct an attribution matrix and the complete linkage algorithm is employed to conduct clustering of the inter-session clusters. A matched cluster purity and coverage of 87.1% was obtained on the NIST 2008 SRE corpus.

Using Fiber Bragg Grating (FBG) sensors to measure vertical displacements of bridges : a preliminary study

In many bridges, vertical displacements are the most relevant parameter for monitoring in the both short and long term. However, it is difficult to measure vertical displacements of bridges and yet they are among the most important indicators of structural behaviour. Therefore, it prompts a need to develop a simple, inexpensive and yet more practical method to measure vertical displacements of bridges. With the development of fiber-optics technologies, fiber Bragg grating (FBG) sensors have been widely used in structural health monitoring. The advantages of these sensors over the conventional sensors include multiplexing capabilities, high sample rate, small size and electro magnetic interference (EMI) immunity. In this paper, methods of vertical displacement measurements of bridges are first reviewed. Then, FBG technology is briefly introduced including principle, sensing system, characteristics and different types of FBG sensors. Finally, the methodology of vertical displacement measurements using FBG sensors is presented and a trial test is described. It is concluded that using FBG sensors is feasible to measure vertical displacements of bridges. This method can be used to understand global behaviour of bridge‘s span and can further develop for structural health monitoring techniques such as damage detection.

Critical gap estimation by numerical and statistical highest likelihood search

Many traffic situations require drivers to cross or merge into a stream having higher priority. Gap acceptance theory enables us to model such processes to analyse traffic operation. This discussion demonstrated that numerical search fine tuned by statistical analysis can be used to determine the most likely critical gap for a sample of drivers, based on their largest rejected gap and accepted gap. This method shares some common features with the Maximum Likelihood Estimation technique (Troutbeck 1992) but lends itself well to contemporary analysis tools such as spreadsheet and is particularly analytically transparent. This method is considered not to bias estimation of critical gap due to very small rejected gaps or very large rejected gaps. However, it requires a sufficiently large sample that there is reasonable representation of largest rejected gap/accepted gap pairs within a fairly narrow highest likelihood search band.

Empirical research in business process management : introduction to the special issue

In this editorial letter, we provide the readers of Information Systems and e-Business Management with an introduction to Business Process Management and the challenges of empirical research in this field. We then briefly describe selected examples of current research efforts in this fields and how the papers accepted for this special issue contribute to extending our body of knowledge.

Exposure to particles from laser printers operating within office workplaces

While recent research has provided valuable information as to the composition of laser printer particles, their formation mechanisms, and explained why some printers are emitters whilst others are low emitters, fundamental questions relating to the potential exposure of office workers remained unanswered. In particular, (i) what impact does the operation of laser printers have on the background particle number concentration (PNC) of an office environment over the duration of a typical working day?; (ii) what is the airborne particle exposure to office workers in the vicinity of laser printers; (iii) what influence does the office ventilation have upon the transport and concentration of particles?; (iv) is there a need to control the generation of, and/or transport of particles arising from the operation of laser printers within an office environment?; (v) what instrumentation and methodology is relevant for characterising such particles within an office location? We present experimental evidence on printer temporal and spatial PNC during the operation of 107 laser printers within open plan offices of five buildings. We show for the first time that the eight-hour time-weighted average printer particle exposure is significantly less than the eight-hour time-weighted local background particle exposure, but that peak printer particle exposure can be greater than two orders of magnitude higher than local background particle exposure. The particle size range is predominantly ultrafine (< 100nm diameter). In addition we have established that office workers are constantly exposed to non-printer derived particle concentrations, with up to an order of magnitude difference in such exposure amongst offices, and propose that such exposure be controlled along with exposure to printer derived particles. We also propose, for the first time, that peak particle reference values be calculated for each office area analogous to the criteria used in Australia and elsewhere for evaluating exposure excursion above occupational hazardous chemical exposure standards. A universal peak particle reference value of 2.0 x 104 particles cm-3 has been proposed.

Here’s a story : using student podcasts to raise awareness of language

Thirty-five years ago, a landmark article entitled 'What The "Good Language Learner" Can Teach Us' suggested that if more was known about what 'successful learners' did, then those strategies could be taught to poorer learners to enhance learning (Rubin, 1975, p. 42). Since publication of Rubin's article, language instruction has begun to encompass technological applications (Chinnery, 2006) through mobile-assisted language learning (MALL or m-learning) like podcasts. Podcasting extends the classroom, offers convenience for diverse learners, and provides authentic listening opportunities. Although the effects of podcasting in higher education have yet to be investigated (Educause, 2007), this article describes how action research lead to the creation of a student learning strategy webpage featuring peer podcasts and successful language learning strategies in higher education.

Learning and teaching from the edge to centre stage : Critical factors in embedding sustainable university-wide engagement in external awards and grants funding initiatives.

Teaching awards, grants and fellowships are strategies used to recognise outstanding contributions to learning and teaching, encourage innovation, and to shift learning and teaching from the edge to centre stage. Examples range from school, faculty and institutional award and grant schemes to national schemes such as those offered by the Australian Learning and Teaching Council (ALTC), the Carnegie Foundation for the Advancement of Teaching in the United States, and the Fund for the Development of Teaching and Learning in higher education in the United Kingdom. The Queensland University of Technology (QUT) has experienced outstanding success in all areas of the ALTC funding since the inception of the Carrick Institute for Learning and Teaching in 2004. This paper reports on a study of the critical factors that have enabled sustainable and resilient institutional engagement with ALTC programs. As a lens for examining the QUT environment and practices, the study draws upon the five conditions of the framework for effective dissemination of innovation developed by Southwell, Gannaway, Orrell, Chalmers and Abraham (2005, 2010): 1. Effective, multi-level leadership and management 2. Climate of readiness for change 3. Availability of resources 4. Comprehensive systems in institutions and funding bodies 5. Funding design The discussion on the critical factors and practical and strategic lessons learnt for successful university-wide engagement offer insights for university leaders and staff who are responsible for learning and teaching award, grant and associated internal and external funding schemes.

Dynamics of railway wagons subjected to braking torques on defective tracks

It is well known that track defects cause profound effects to the dynamics of railway wagons; normally such problems are examined for cases of wagons running at a constant speed. Brake/traction torques affect the speed profile due to the wheel–rail contact characteristics but most of the wagon–track interaction models do not explicitly consider them in simulation. The authors have recently published a model for the dynamics of wagons subject to braking traction torques on a perfect track by explicitly considering the pitch degree of freedom for wheelsets. The model is extended for cases of lateral and vertical track geometry defects and worn railhead and wheel profiles. This paper presents the results of the analyses carried out using the model extended to the dynamics of wagons containing less ideal wheel profiles running on tracks with geometry defects and worn rails.

The beliefs which motivate young male and female drivers to speed : a comparison of low and high intenders

In Australia, young drivers aged 17 to 24 years, and particularly males, have the highest risk of being involved in a fatal crash. Investigation of young drivers’ beliefs allows for a greater understanding of their involvement in risky behaviours, such as speeding, as beliefs are associated with intentions, the antecedent to behaviour. The theory of planned behaviour (TPB) was used to conceptualise beliefs using a scenario based questionnaire distributed to licensed drivers (N = 398). The questionnaire measured individual’s beliefs and intentions to speed in a particular situation. Consistent with a TPB-based approach, the beliefs of those with low intentions to speed (‘low intenders’) were compared with the beliefs of those with high intentions (‘high intenders’) with such comparisons conducted separately for males and females. Overall, significant differences in the beliefs held by low and high intenders and for both females and males were found. Specifically, for females, it was found that high intenders were significantly more likely to perceive advantages of speeding, less likely to perceive disadvantages, and more likely to be encouraged to speed on familiar and inappropriately signed roads than female low intenders. Females, however, did not differ in their perceptions of support from friends, with all females reporting some level of disapproval from most friends and all females (i.e., low and high intenders) reporting approval to speed from their male friends. The results for males revealed that high intenders were significantly more likely to speed on familiar and inappropriately signed roads as well as having greater perceptions of support from all friends, except from those friends with whom they worked. Low and high intending males did not differ in their perceptions of the advantages and disadvantages of speeding, with the exception of feelings of excitement whereby high intenders reported speeding to be more exciting than low intenders. The findings are discussed in terms of how they may directly inform the content of mass media and public education campaigns aimed at encouraging young drivers to slow down.

Scaling analysis of the unsteady natural convection boundary layer adjacent to an inclined plate for Pr > 1 following instantaneous heating

The unsteady natural convection boundary layer adjacent to an instantaneously heated inclined plate is investigated using an improved scaling analysis and direct numerical simulations. The development of the unsteady natural convection boundary layer following instantaneous heating may be classified into three distinct stages including a start-up stage, a transitional stage and a steady state stage, which can be clearly identified in the analytical and numerical results. Major scaling relations of the velocity and thicknesses and the flow development time of the natural convection boundary layer are obtained using triple-layer integral solutions and verified by direct numerical simulations over a wide range of flow parameters.

Quantification of the accuracy of MRI generated 3D models of long bones compared to CT generated 3D models

Orthopaedic fracture fixation implants are increasingly being designed using accurate 3D models of long bones based on computer tomography (CT). Unlike CT, magnetic resonance imaging (MRI) does not involve ionising radiation and is therefore a desirable alternative to CT. This study aims to quantify the accuracy of MRI-based 3D models compared to CT-based 3D models of long bones. The femora of five intact cadaver ovine limbs were scanned using a 1.5T MRI and a CT scanner. Image segmentation of CT and MRI data was performed using a multi-threshold segmentation method. Reference models were generated by digitising the bone surfaces free of soft tissue with a mechanical contact scanner. The MRI- and CT-derived models were validated against the reference models. The results demonstrated that the CT-based models contained an average error of 0.15mm while the MRI-based models contained an average error of 0.23mm. Statistical validation shows that there are no significant differences between 3D models based on CT and MRI data. These results indicate that the geometric accuracy of MRI based 3D models was comparable to that of CT-based models and therefore MRI is a potential alternative to CT for generation of 3D models with high geometric accuracy.

Right to the city, desire for the suburb?

The 2000s have been a lively decade for cities. The Worldwatch Institute estimated that 2007 was the first year in human history that more people worldwide lived in cities than the countryside. Globalisation and new digital media technologies have generated the seemingly paradoxical outcome that spatial location came to be more rather than less important, as combinations of firms, industries, cultural activities and creative talents have increasingly clustered around a select node of what have been termed “creative cities,” that are in turn highly networked into global circuits of economic capital, political power and entertainment media. Intellectually, the period has seen what the UCLA geographer Ed Soja refers to as the spatial turn in social theory, where “whatever your interests may be, they can be significantly advanced by adopting a critical spatial perspective”. This is related to the dynamic properties of socially constructed space itself, or what Soja terms “the powerful forces that arise from socially produced spaces such as urban agglomerations and cohesive regional economies,” with the result that “what can be called the stimulus of socio-spatial agglomeration is today being assertively described as the primary cause of economic development, technological innovation, and cultural creativity”

Contribution of take-out food consumption to socioeconomic differences in fruit and vegetable intake : a mediation analysis

Lower fruit and vegetable intake among socioeconomically disadvantaged groups has been well documented, and may be a consequence of a higher consumption of take-out foods. This study examined whether, and to what extent, take-out food consumption mediated (explained) the association between socioeconomic position and fruit and vegetable intake. A cross-sectional postal survey was conducted among 1500 randomly selected adults aged 25–64 years in Brisbane, Australia in 2009 (response rate = 63.7%, N = 903). A food frequency questionnaire assessed usual daily servings of fruits and vegetables (0 to 6), overall take-out consumption (times/week) and the consumption of 22 specific take-out items (never to ≥once/day). These specific take-out items were grouped into “less healthy” and “healthy” choices and indices were created for each type of choice (0 to 100). Socioeconomic position was ascertained by education. The analyses were performed using linear regression, and a bootstrap re-sampling approach estimated the statistical significance of the mediated effects. Mean daily serves of fruits and vegetables was 1.89 (SD 1.05) and 2.47 (SD 1.12) respectively. The least educated group were more likely to consume fewer serves of fruit (B= –0.39, p<0.001) and vegetables (B= –0.43, p<0.001) compared with the highest educated. The consumption of “less healthy” take-out food partly explained (mediated) education differences in fruit and vegetable intake; however, no mediating effects were observed for overall and “healthy” take-out consumption. Regular consumption of “less healthy” take-out items may contribute to socioeconomic differences in fruit and vegetable intake, possibly by displacing these foods.

Cyclists' experiences of harassment from motorists : findings from a survey of cyclists in Queensland, Australia

Objective Harassment from motorists is a major constraint on cycling that has been under-researched. We examined incidence and correlates of harassment of cyclists. Methods Cyclists in Queensland, Australia were surveyed in 2009 about their experiences of harassment while cycling, from motor vehicle occupants. Respondents also indicated the forms of harassment they experienced. Logistic regression modeling was used to examine gender and other correlates of harassment. Results Of 1830 respondents, 76% of men and 72% of women reported harassment in the previous 12 months. The most reported forms of harassment were driving too close (66%), shouting abuse (63%), and making obscene gestures/sexual harassment (45%). Older age, overweight/obesity, less cycling experience (< 2 years) and less frequent cycling (< 3 days/week) were associated with less likelihood of harassment, while living in highly advantaged areas (SEIFA deciles 8 or 9), cycling for recreation, and cycling for competition were associated with increased likelihood of harassment. Gender was not associated with reports of harassment. Conclusions Efforts to decrease harassment should include a closer examination of the circumstances that give rise to harassment, as well as fostering road environments and driver attitudes and behaviors that recognize that cyclists are legitimate road users.

Cross likelihood ratio based speaker clustering using eigenvoice models

This paper proposes the use of eigenvoice modeling techniques with the Cross Likelihood Ratio (CLR) as a criterion for speaker clustering within a speaker diarization system. The CLR has previously been shown to be a robust decision criterion for speaker clustering using Gaussian Mixture Models. Recently, eigenvoice modeling techniques have become increasingly popular, due to its ability to adequately represent a speaker based on sparse training data, as well as an improved capture of differences in speaker characteristics. This paper hence proposes that it would be beneficial to capitalize on the advantages of eigenvoice modeling in a CLR framework. Results obtained on the 2002 Rich Transcription (RT-02) Evaluation dataset show an improved clustering performance, resulting in a 35.1% relative improvement in the overall Diarization Error Rate (DER) compared to the baseline system.