Condition deterioration prediction of bridge elements using Dynamic Bayesian Networks (DBNs)

The ability of bridge deterioration models to predict future condition provides significant advantages in improving the effectiveness of maintenance decisions. This paper proposes a novel model using Dynamic Bayesian Networks (DBNs) for predicting the condition of bridge elements. The proposed model improves prediction results by being able to handle, deterioration dependencies among different bridge elements, the lack of full inspection histories, and joint considerations of both maintenance actions and environmental effects. With Bayesian updating capability, different types of data and information can be utilised as inputs. Expert knowledge can be used to deal with insufficient data as a starting point. The proposed model established a flexible basis for bridge systems deterioration modelling so that other models and Bayesian approaches can be further developed in one platform. A steel bridge main girder was chosen to validate the proposed model.

Validation of a new hand-held electronic data capture method for continuous monitoring of subjective appetite sensations

Background When large scale trials are investigating the effects of interventions on appetite, it is paramount to efficiently monitor large amounts of human data. The original hand-held Electronic Appetite Ratings System (EARS) was designed to facilitate the administering and data management of visual analogue scales (VAS) of subjective appetite sensations. The purpose of this study was to validate a novel hand-held method (EARS II (HP® iPAQ)) against the standard Pen and Paper (P&P) method and the previously validated EARS. Methods Twelve participants (5 male, 7 female, aged 18-40) were involved in a fully repeated measures design. Participants were randomly assigned in a crossover design, to either high fat (>48% fat) or low fat (<28% fat) meal days, one week apart and completed ratings using the three data capture methods ordered according to Latin Square. The first set of appetite sensations was completed in a fasted state, immediately before a fixed breakfast. Thereafter, appetite sensations were completed every thirty minutes for 4h. An ad libitum lunch was provided immediately before completing a final set of appetite sensations. Results Repeated measures ANOVAs were conducted for ratings of hunger, fullness and desire to eat. There were no significant differences between P&P compared with either EARS or EARS II (p > 0.05). Correlation coefficients between P&P and EARS II, controlling for age and gender, were performed on Area Under the Curve ratings. R2 for Hunger (0.89), Fullness (0.96) and Desire to Eat (0.95) were statistically significant (p < 0.05). Conclusions EARS II was sensitive to the impact of a meal and recovery of appetite during the postprandial period and is therefore an effective device for monitoring appetite sensations. This study provides evidence and support for further validation of the novel EARS II method for monitoring appetite sensations during large scale studies. The added versatility means that future uses of the system provides the potential to monitor a range of other behavioural and physiological measures often important in clinical and free living trials.

Too sleepy to drive : self-perception and regulation of driving when sleepy

Background: Sleepiness is a direct contributor to a substantial proportion of fatal and severe road cashes. A number of technological solutions designed to detect sleepiness have been developed, but self-awareness of increasing sleepiness remains a critical component in on-road strategies for mitigating this risk. In order to take appropriate action when sleepy, drivers’ perceptions of their level of sleepiness must be accurate. Aims: This study aimed to assess capacity to accurately identify sleepiness and self-regulate driving cessation during a validated driving simulator task. Participants: Participants comprised 26 young adult drivers (20-28 years). The drivers had open licenses but no other exclusion criteria where used. Methods: Participants woke at 5am, and took part in a laboratory-based hazard perception driving simulation, either at mid-morning or mid-afternoon. Established physiological measures (including EEG) and subjective measures (sleepiness ratings) previously found sensitive to changes in sleepiness levels were utilised. Participants were instructed to ‘drive’ until they believed that sleepiness had impaired their ability to drive safely. They were then offered a nap opportunity. Results: The mean duration of the drive before cessation was 39 minutes (±18 minutes). Almost all (23/26) of the participants then achieved sleep during the nap opportunity. These data suggest that the participants’ perceptions of sleepiness were specific. However, EEG data from a number of participants suggested very high levels of sleepiness prior to driving cessation, suggesting poor sensitivity. Conclusions: Participants reported high levels of sleepiness while driving after very moderate sleep restriction. They were able to identify increasing sleepiness during the test period, could decide to cease driving and in most cases were sufficiently sleepy to achieve sleep during the daytime session. However, the levels of sleepiness achieved prior to driving cessation suggest poor accuracy in self-perception and regulation. This presents practical issues for the implementation of fatigue and sleep-related strategies to improve driver safety.

Integrated health prediction of bridge systems using dynamic object oriented Bayesian networks (DOOBNS)

The serviceability and safety of bridges are crucial to people’s daily lives and to the national economy. Every effort should be taken to make sure that bridges function safely and properly as any damage or fault during the service life can lead to transport paralysis, catastrophic loss of property or even casualties. Nonetheless, aggressive environmental conditions, ever-increasing and changing traffic loads and aging can all contribute to bridge deterioration. With often constrained budget, it is of significance to identify bridges and bridge elements that should be given higher priority for maintenance, rehabilitation or replacement, and to select optimal strategy. Bridge health prediction is an essential underpinning science to bridge maintenance optimization, since the effectiveness of optimal maintenance decision is largely dependent on the forecasting accuracy of bridge health performance. The current approaches for bridge health prediction can be categorised into two groups: condition ratings based and structural reliability based. A comprehensive literature review has revealed the following limitations of the current modelling approaches: (1) it is not evident in literature to date that any integrated approaches exist for modelling both serviceability and safety aspects so that both performance criteria can be evaluated coherently; (2) complex system modelling approaches have not been successfully applied to bridge deterioration modelling though a bridge is a complex system composed of many inter-related bridge elements; (3) multiple bridge deterioration factors, such as deterioration dependencies among different bridge elements, observed information, maintenance actions and environmental effects have not been considered jointly; (4) the existing approaches are lacking in Bayesian updating ability to incorporate a variety of event information; (5) the assumption of series and/or parallel relationship for bridge level reliability is always held in all structural reliability estimation of bridge systems. To address the deficiencies listed above, this research proposes three novel models based on the Dynamic Object Oriented Bayesian Networks (DOOBNs) approach. Model I aims to address bridge deterioration in serviceability using condition ratings as the health index. The bridge deterioration is represented in a hierarchical relationship, in accordance with the physical structure, so that the contribution of each bridge element to bridge deterioration can be tracked. A discrete-time Markov process is employed to model deterioration of bridge elements over time. In Model II, bridge deterioration in terms of safety is addressed. The structural reliability of bridge systems is estimated from bridge elements to the entire bridge. By means of conditional probability tables (CPTs), not only series-parallel relationship but also complex probabilistic relationship in bridge systems can be effectively modelled. The structural reliability of each bridge element is evaluated from its limit state functions, considering the probability distributions of resistance and applied load. Both Models I and II are designed in three steps: modelling consideration, DOOBN development and parameters estimation. Model III integrates Models I and II to address bridge health performance in both serviceability and safety aspects jointly. The modelling of bridge ratings is modified so that every basic modelling unit denotes one physical bridge element. According to the specific materials used, the integration of condition ratings and structural reliability is implemented through critical failure modes. Three case studies have been conducted to validate the proposed models, respectively. Carefully selected data and knowledge from bridge experts, the National Bridge Inventory (NBI) and existing literature were utilised for model validation. In addition, event information was generated using simulation to demonstrate the Bayesian updating ability of the proposed models. The prediction results of condition ratings and structural reliability were presented and interpreted for basic bridge elements and the whole bridge system. The results obtained from Model II were compared with the ones obtained from traditional structural reliability methods. Overall, the prediction results demonstrate the feasibility of the proposed modelling approach for bridge health prediction and underpin the assertion that the three models can be used separately or integrated and are more effective than the current bridge deterioration modelling approaches. The primary contribution of this work is to enhance the knowledge in the field of bridge health prediction, where more comprehensive health performance in both serviceability and safety aspects are addressed jointly. The proposed models, characterised by probabilistic representation of bridge deterioration in hierarchical ways, demonstrated the effectiveness and pledge of DOOBNs approach to bridge health management. Additionally, the proposed models have significant potential for bridge maintenance optimization. Working together with advanced monitoring and inspection techniques, and a comprehensive bridge inventory, the proposed models can be used by bridge practitioners to achieve increased serviceability and safety as well as maintenance cost effectiveness.

Improving stability of a DFIG-based wind power system with tuned damping controller

This paper focuses on the implementation of a damping controller for the doubly fed induction generator (DFIG) system. Coordinated tuning of the damping controller to enhance the damping of the oscillatory modes is presented using bacterial foraging technique. The effect of the tuned damping controller on converter ratings of the DFIG system is also investigated. The results of both eigenvalue analysis and the time-domain simulation studies are presented to elucidate the effectiveness of the tuned damping controller in the DFIG system. The improvement of the fault ride-through capability of the system is also demonstrated.

Multiuser virtual safety training system for tower crane dismantlement

Tower crane dismantling is one of the most dangerous activities in the construction industry. Tower crane erection and dismantlement causes 10–12% of the fatalities of all crane accidents. The nature of the task is such that off-the-job training is not practicable, and the knowledge and expertise needed has to be gained on the job. However, virtual trainers such as Microsoft Flight Simulator for airplane pilots and mission rehearsal exercise (MRE) for army personnel have been developed and are known to provide a highly successful means of overcoming the risks involved in such on-the-job learning and clearly have potential in construction situations. This paper describes the newly developed multiuser virtual safety training system (MVSTS) aimed at providing a similar learning environment for those involved in tower crane dismantlement. The proposed training system is developed by modifying an existing game engine. Within the close-to-reality virtual environment, trainees can participate in a virtual dismantling process. During the process, they learn the correct dismantling procedure and working location and to cooperate with other trainees by virtually dismantling the crane. The system allows the trainees to experience the complete procedure in a risk-free environment. A case study is provided to demonstrate how the system works and its practical application. The proposed system was evaluated by interviews with 30 construction experts with different backgrounds, divided into three groups according to their experience and trained by the traditional and virtual methods, respectively. The results indicate that the trainees of the proposed system generally learned better than those using the traditional method. The ratings also indicate that the system generally has great potential as a training platform.

Reframing evaluation of learning and teaching: An approach to change

Evaluation practices in the Higher Education sector have been criticised for having unclear purpose and principles; ignoring the complexity and changing nature of learning and teaching and the environments in which they occur; relying almost exclusively on student ratings of teachers working in classroom settings; lacking reliability and validity; using data for inappropriate purposes; and focusing on accountability and marketing rather than the improvement of learning and teaching. In response to similar criticism from stakeholders, in 2011 Queensland University of Technology (QUT) began a project which aims to reframe the organisation’s approach to the evaluation of learning and teaching. This paper describes the existing evaluation system; the emergence and early development of the project; and formulation of a conceptual framework identifying key dimensions of evaluation. It then compares the draft framework with other conceptualisations and models of evaluation identified in the literature, to determine its validity and suitability for supporting QUT’s plans for the future. Overall, the paper represents a structured evaluation of the REFRAME project at a particular point in its lifecycle. Given that the project follows an evidence based, practice-led process and applies an ongoing action research cycle, the findings are presented in the belief that QUT’s experience is broadly applicable to other institutions which may be contemplating change in relation to evaluation of learning and teaching.

Rating the Audience : the Business of Media

Knowing, measuring and understanding media audiences have become a multi-billion dollar business. But the convention that underpins that business, audience ratings, is in crisis. Rating the Audience is the first book to show why and how audience ratings research became a convention, an agreement, and the first to interrogate the ways that agreement is now under threat. Taking a historical approach, the book looks at the evolution of audience ratings and the survey industry. It goes on to analyse today's media environment, looking at the role of the internet and the increased difficulties it presents for measuring audiences. The book covers all the major players and controversies, such as Facebook's privacy rulings and Google's alliance with Nielsen. Offering the first real comparative study, it will be critical for media students and professionals.

Effects of acute multi-nutrient supplementation on rugby union match performance and recovery

Aim: To determine the effects of an acute multi-nutrient supplement on physiological, performance and recovery responses to intermittent-sprint running and muscular damage during rugby union matches. Methods: Using a randomised, double-blind, cross-over design, twelve male rugby union players ingested either 75 g of a comprehensive multi-nutrient supplement (SUPP), [Musashi] or 1 g of a taste and carbohydrate matched placebo (PL) for 5 days pre-competition. Competitive rugby union game running performance was then measured using 1 Hz GPS data (SPI10, SPI elite, GPSports), in addition to associated blood draws, vertical jump assessments and ratings of perceived muscular soreness (MS) pre, immediately post and 24 h post-competition. Baseline (BL) GPS data was collected during six competition rounds preceding data collection. Results: No significant differences were observed between supplement conditions for all game running, vertical jump, and ratings of perceived muscular soreness. However, effect size analysis indicated SUPP ingestion increased 1st half very high intensity running (VHIR) mean speed (d = 0.93) and 2nd half relative distance (m/min) (d = 0.97). Further, moderate increases in 2nd half VHIR distance (d = 0.73), VHIR m/min (d = 0.70) and VHIR mean speed (d = 0.56) in SUPP condition were also apparent. Moreover, SUPP demonstrated significant increases in 2nd half dist m/min, total game dist m/min and total game HIR m/min compared with BL data (P < 0.05). Further, large ES increases in VHIR time (d = 0.88) and moderate increases in 2nd half HIR m/min (d = 0.65) and 2nd half VHIR m/min (d = 0.74) were observed between SUPP and BL. Post-game aspartate aminotransferase (AST) (d = 1.16) and creatine kinase (CK) (d = 0.97) measures demonstrated increased ES values with SUPP, while AST and CK values correlated with 2nd half VHIR distance (r = −0.71 and r = −0.76 respectively). Elevated c-reactive protein (CRP) was observed post-game in both conditions, however was significantly blunted with SUPP (P = 0.05). Additionally, pre-game (d = 0.98) and post-game (d = 0.96) increases in cortisol (CORT) were apparent with SUPP. No differences were apparent between conditions for pH, lactate, glucose, HCO3, vertical jump assessments and MS (P > 0.05). Conclusion: These findings suggest SUPP may assist in the maintenance of VHIR speeds and distances covered during rugby union games, possibly via the buffering qualities of SUPP ingredients (i.e. caffeine, creatine, bicarbonate). While the mechanisms for these findings are unclear, the similar pH between conditions despite additional VHIR during SUPP may support this conclusion. Finally, correlations between increased work completed at very high intensities and muscular degradation in SUPP conditions, may mask any anti-catabolic properties of supplementation.

Minimum important difference between patients with rheumatoid arthritis : the patient's perspective

OBJECTIVE: To determine the point at which differences in clinical assessment scores on physical ability, pain and overall condition are sufficiently large to correspond to a subjective perception of a meaningful difference from the perspective of the patient. METHODS: Forty patients with a diagnosis of rheumatoid arthritis participated in an evening of clinical assessment and one-on-one conversations with each other regarding their arthritic condition. The assessments included tender and swollen joint counts, clinician and patient global assessments, participant assessment of pain and the Health Assessment Questionnaire (HAQ) on physical ability. After each conversation, participants rated themselves relative to their conversational partner on physical ability, pain and overall condition. These subjective comparative ratings were compared to the differences of the individual clinical assessments. RESULTS: In total there were 120 conversations. Generally participants judged themselves as less disabled than others. They rated themselves as "somewhat better" than their conversation partner when they had a (mean) 7% better score on the HAQ, 6% less pain, and 9% better global assessment. In contrast, they rated themselves as "somewhat worse" when they had a (mean) 16% worse score on the HAQ, 16% more pain, and 29% worse global assessment. CONCLUSIONS: Patients view clinically important differences in an asymmetric manner. These results can provide guidance in interpreting results and planning clinical trials.

Concurrent and longitudinal links between children’s and their friends’ antisocial and prosocial behavior in preschool

Concurrent and longitudinal links between children’s own and their nominated best friends’ antisocial and prosocial behavior were studied in a normative sample of 3–5-year-olds (N = 203). Moderating effects of age and gender were also explored. Subscales of the Strength and Difficulties Questionnaire (SDQ) were used to obtain teacher ratings of behavior for each target child and his/her nominated best friends. Nomination of best friends with higher levels of antisocial behavior and lower levels of prosocial behavior was concurrently linked to more antisocial behavior in boys. Nomination of highly prosocial best friends was concurrently linked to more prosocial behavior in both boys and girls. However, the study found no longitudinal effects of best friends’ behavior on target child’s behavior over a one-year period. A group of children who nominated no best friends at T1 were generally perceived as less prosocial, but not more antisocial, than other children. © 2011 Elsevier Inc. All rights reserved.

Intercultural competence in engineering education : who are we teaching?

BACKGROUND There is little doubt that our engineering graduates’ ability to identify cultural differences and their potential to impact on engineering projects, and to work effectively with these differences is of key importance in the modern engineering practice. Within engineering degree programs themselves there is also a significant need to recognise the impact of changing student and staff profiles on what happens in the classroom. The research described in this paper forms part of a larger project exploring issues of intercultural competence in engineering. PURPOSE This paper presents an observational and survey study of undergraduate and postgraduate engineering students from four institutions working in groups on tasks with a purely technical focus, or with a cultural and humanitarian element. The study sought to explore how students rate their own intercultural competence and team process and whether any differences exist depending on the nature of the task they are working on. We also investigated whether any differences were evident between groups of first year, second year and postgraduate students. DESIGN/METHOD The study used the miniCQS instrument (Ang & Van Dyne, 2008) and a Bales Interaction Process Analysis based scale (Bales, 1950; Carney, 1976) to collect students self ratings of group process, task management, and cultural experience and behaviour. The Bales IPA was also used for coding video observations of students working in groups. Survey data were used to form descriptive variables to compare outcomes across the different tasks and contexts. Observations analysed in Nvivo were used to provide commentary and additional detail on the quantitative data. RESULTS The results of the survey indicated consistent mean scores on each survey item for each group of students, despite vastly different tasks, student backgrounds and educational contexts. Some small, statistically significant mean differences existed, offering some basic insights into how task and student group composition could affect self ratings. Overall though, the results suggest minimal shift in how students view group function and their intercultural experience, irrespective of differing educational experience. CONCLUSIONS The survey results, contrasted with group observations, indicate that either students are not translating their experience (in the group tasks) into critical self assessment of their cultural competence and teamwork, or that they become more critical of team performance and cultural competence as their competence in these areas grows, so their ratings remain consistent. Both outcomes indicate that students need more intensive guidance to build their critical self and peer assessment skills in these areas irrespective of their year level of study.

From tiers to tables – enhancing student experience through collaborative learning spaces

BACKGROUND Collaborative and active learning have been clearly identified as ways students can engage in learning with each other and the academic staff. Traditional tier based lecture theatres and the didactic style they engender are not popular with students today as evidenced by the low attendance rates for lectures. Many universities are installing spaces designed with tables for group interaction with evolutions on spaces such as the TEAL (Technology Enabled Active Learning) (Massachusetts Institute of Technology, n.d.) and SCALE-UP (Student-Centred Activities for Large-Enrolment Undergraduate Programs) (North Carolina State University, n.d.) models. Technology advances in large screen computers and applications have also aided the move to these collaborative spaces. How well have universities structured learning using these spaces and how have students engaged with the content, technology, space and each other? This paper investigates the application of collaborative learning in such spaces for a cohort of 800+ first year engineers in the context of learning about and developing professional skills representative of engineering practice. PURPOSE To determine whether moving from tiers to tables enhances the student experience. Does utilising technology rich, activity based, collaborative learning spaces lead to positive experiences and active engagement of first year undergraduate engineering students? In developing learning methodology and approach in new learning spaces, what needs to change from a more traditional lecture and tutorial configuration? DESIGN/METHOD A post delivery review and analysis of outcomes was undertaken to determine how well students and tutors engaged with learning in new collaborative learning spaces. Data was gathered via focus group and survey of tutors, students survey and attendance observations. The authors considered the unit delivery approach along with observed and surveyed outcomes then conducted further review to produce the reported results. RESULTS Results indicate high participation in the collaborative sessions while the accompanying lectures were poorly attended. Students reported a high degree of satisfaction with the learning experience; however more investigation is required to determine the degree of improvement in retained learning outcomes. Survey feedback from tutors found that students engaged well in the activities during tutorials and there was an observed improvement in the quality of professional practice modelled by students during sessions. Student feedback confirmed the positive experiences in these collaborative learning spaces with 30% improvement in satisfaction ratings from previous years. CONCLUSIONS It is concluded that the right mix of space, technology and appropriate activities does engage students, improve participation and create a rich experience to facilitate potential for improved learning outcomes. The new Collaborative Teaching Spaces, together with integrated technology and tailored activities, has transformed the delivery of this unit and improved student satisfaction in tutorials significantly.

Intratherapist reliability in the rating of scapula posture in multiple planes of reference

Background: Evaluation of scapular posture is a fundamental component in the clinical evaluation of the upper quadrant. This study examined the intrarater reliability of scapular posture ratings. Methods: A test-retest reliability investigation was undertaken with one week between assessment sessions. At each session physical therapists conducted visual assessments of scapula posture (relative to the thorax) in five different scapula postural planes (plane of scapula, sagittal plane, transverse plane, horizontal plane, and vertical plane). These five plane ratings were performed for four different scapular posture perturbating conditions (rest, isometric shoulder; flexion, abduction, and external rotation). Results. A total of 100 complete scapular posture ratings (50 left, 50 right) were undertaken at each assessment. The observed agreement between the test and retest postural plane ratings ranged from 59% to 87%; 16 of the 20 plane-condition combinations exceeded 75% observed agreement. Kappa (and prevalence adjusted bias adjusted kappa) values were inconsistent across the postural planes and perturbating conditions. Conclusions: This investigation generally revealed fair to moderate intrarater reliability in the rating of scapular posture by visual inspection. However, enough disagreement between assessments was present to warrant caution when interpreting perceived changes in scapula position between longitudinal assessments using visual inspection alone.

Action research and unit improvement in higher education : a case study approach

Student satisfaction data has been collected on a national basis in Australia since 1972. In recent years this data has been used by federal government agencies to allocate funding, and by students in selecting their universities of choice. The purpose of this paper is to present the findings of an action research project designed to identify and implement unit improvement initiatives over a three year period for an underperforming unit. This research utilises student survey data and teacher reflections to identify areas of unit improvement, with a view to aligning learning experiences, teaching and assessment to learning outcomes and improved student satisfaction. This research concludes that whilst a voluntary student survey system may be imperfect, it nevertheless provides important data that can be utilised to the benefit of the unit, learning outcomes and student satisfaction ratings, as well as wider course related outcomes. Extrapolation of these findings is recommended to other underperforming units.