A safety adapted car following model for traffic safety studies

Traffic safety studies demand more than what current micro-simulation models can provide as they presume that all drivers exhibit safe behaviors. All the microscopic traffic simulation models include a car following model. This paper highlights the limitations of the Gipps car following model ability to emulate driver behavior for safety study purposes. A safety adapted car following model based on the Gipps car following model is proposed to simulate unsafe vehicle movements, with safety indicators below critical thresholds. The modifications are based on the observations of driver behavior in real data and also psychophysical notions. NGSIM vehicle trajectory data is used to evaluate the new model and short following headways and Time To Collision are employed to assess critical safety events within traffic flow. Risky events are extracted from available NGSIM data to evaluate the modified model against them. The results from simulation tests illustrate that the proposed model can predict the safety metrics better than the generic Gipps model. The outcome of this paper can potentially facilitate assessing and predicting traffic safety using microscopic simulation.

AEHRC & QUT at TREC 2011 Medical Track : a concept-based information retrieval approach

The Australian e-Health Research Centre and Queensland University of Technology recently participated in the TREC 2011 Medical Records Track. This paper reports on our methods, results and experience using a concept-based information retrieval approach. Our concept-based approach is intended to overcome specific challenges we identify in searching medical records. Queries and documents are transformed from their term-based originals into medical concepts as de ned by the SNOMED-CT ontology. Results show our concept-based approach performed above the median in all three performance metrics: bref (+12%), R-prec (+18%) and Prec@10 (+6%).

Qualitative and quantitative analysis of six sigma in service organizations

The concept of Six Sigma was initiated in the 1980s by Motorola. Since then it has been implemented in several manufacturing and service organizations. Till now Six Sigma implementation is mostly limited to healthcare and financial services in private sector. Its implementation is now gradually picking up in services such as call center, education, construction and related engineering etc. in private as well as public sector. Through a literature review, a questionnaire survey, and multiple case study approach the paper develops a conceptual framework to facilitate widening the scope of Six Sigma implementation in service organizations. Using grounded theory methodology, this study develops theory for Six Sigma implementation in service organizations. The study involves a questionnaire survey and case studies to understand and build a conceptual framework. The survey was conducted in service organizations in Singapore and exploratory in nature. The case studies involved three service organizations which implemented Six Sigma. The objective is to explore and understand the issues highlighted by the survey and the literature. The findings confirm the inclusion of critical success factors, critical-to-quality characteristics, and set of tools and techniques as observed from the literature. In case of key performance indicator, there are different interpretations about it in literature and also by industry practitioners. Some literature explain key performance indicator as performance metrics whereas some feel it as key process input or output variables, which is similar to interpretations by practitioners of Six Sigma. The response of not relevant and unknown to us as reasons for not implementing Six Sigma shows the need for understanding specific requirements of service organizations. Though much theoretical description is available about Six Sigma, but there has been limited rigorous academic research on it. This gap is far more pronounced about Six Sigma implementation in service organizations, where the theory is not mature enough. Identifying this need, the study contributes by going through theory building exercise and developing a conceptual framework to understand the issues involving its implementation in service organizations.

Evaluation of the GHR car following model for traffic safety studies

Traffic safety studies mandate more than what existing micro-simulation models can offer as they postulate that every driver exhibits a safe behaviour. All the microscopic traffic simulation models are consisting of a car-following model and the Gazis–Herman–Rothery (GHR) car-following model is a widely used model. This paper highlights the limitations of the GHR car-following model capability to model longitudinal driving behaviour for safety study purposes. This study reviews and compares different version of the GHR model. To empower the GHR model on precise metrics reproduction a new set of car-following model parameters is offered to simulate unsafe vehicle conflicts. NGSIM vehicle trajectory data is used to evaluate the new model and short following headways and Time to Collision are employed to assess critical safety events within traffic flow. Risky events are extracted from available NGSIM data to evaluate the modified model against the generic versions of the GHR model. The results from simulation tests illustrate that the proposed model does predict the safety metrics better than the generic GHR model. Additionally it can potentially facilitate assessing and predicting traffic facilities’ safety using microscopic simulation. The new model can predict Near-miss rear-end crashes.

Evaluation of the luminous environment in open-plan offices with skylights

High Dynamic Range (HDR) imaging was used to collect luminance information at workstations in 2 open-plan office buildings in Queensland, Australia: one lit by skylights, vertical windows and electric light, and another by skylights and electric light. This paper compares illuminance and luminance data collected in these offices with occupant feedback to evaluate these open-plan environments based on available and emerging metrics for visual comfort and glare. This study highlights issues of daylighting quality and measurement specific to open plan spaces. The results demonstrate that overhead glare is a serious threat to user acceptance of skylights, and that electric and daylight integration and controls have a major impact on the perception of daylighting quality. With regards to measurement of visual comfort it was found that the Daylight Glare Probability (DGP) gave poor agreement with occupant reports of discomfort glare in open-plan spaces with skylights, and the CIE Glare Index (CGI) gave the best agreement. Horizontal and vertical illuminances gave no indication of visual comfort in these spaces.

Personal exposure to ultrafine particles at schools microenvironment

This work was motivated by the limited knowledge on personal exposure to ultrafine (UF) particles, especially for children (Mejía et al. 2011). Most research efforts in the past have investigated particle mass concentration and only a limited number of studies have been conducted to quantify other particle metrics, such as particle number, in the classrooms and school microenvironment in general (Diapouli et al. 2008; Guo et al. 2008; Weichenthal et al. 2008; Mullen et al. 2011).

From the Editor

The five articles appearing in this issue reflect the depth of project management research in terms of delineating and clarifying the different philosophical positions, advancing the concepts, and applying innovative research methods. These articles focus on the ontology of project management research (“Foundations of Project Management Research: An Explicit and Six-Facet Ontological Framework” by Gauthier and Ika), project management practices relevant to different types of projects from a practitioner’s perspective (“An Empirical Identification of Project Management Toolsets and a Comparison Among Project Types” by Besner and Hobbs), the effect of project management processes on project performance (“Project Management Knowledge and Effects on Construction Project Outcomes: An Empirical Study” by Chou and Yang), determining the success metrics at different stages of a project (“A Perspective Based Understanding of Project Success” by McLeod, Doolin, and MacDonell), and identifying project success parameters and critical success factors from the point of view of different project actors in largescale projects (“Forecasting Success on Large Projects: Developing Reliable Scales to Predict Multiple Perspectives by Multiple Stakeholders Over Multiple Time Frames” by Turner and Zolin), and understanding project success from the points of view of different project stakeholders...

Post occupancy evaluations relating to discomfort glare : a study of green buildings in Brisbane

Glare indices have yet to be extensively tested in daylit open plan offices, as such there is no effective method to predict discomfort glare within these spaces. This study into discomfort glare in open plan green buildings targeted full-time employees, working under their everyday lighting conditions. Three green buildings in Brisbane were used for data collection, two were Green Star accredited and the other contained innovative daylighting strategies. Data were collected on full-time employees, mostly aged between 30 and 50 years, who broadly reflect the demographics of the wider working population in Australia. It was discovered 36 of the 64 respondents experienced discomfort from both electric and daylight sources at their workspace. The study used a specially tailored post-occupancy evaluation (POE) survey to help assess discomfort glare. Luminance maps extracted from High Dynamic Range (HDR) images were used to capture the luminous environment of the occupants. These were analysed using participant data and the program Evalglare. The physical results indicated no correlation with other developed glare metrics for daylight within these open plan green buildings, including the recently developed Daylight Glare Probability (DGP) Index. The strong influence of vertical illuminance, Ev in the DGP precludes the mostly contrast-based glare from windows observed in this investigation from forming a significant part of this index. Furthermore, critical assessment of the survey techniques used are considered. These will provide insight for further research into discomfort glare in the endeavour to fully develop a suitable glare metric.

Daylighting performance of subtropical multi-residential towers : simulations tools for design decisions

During an intensive design-led workshop multidisciplinary design teams examined options for a sustainable multi-residential tower on an inner urban site in Brisbane (Australia). The main aim was to demonstrate the key principles of daylight to every habitable room and cross-ventilation to every apartment in the subtropical climate while responding to acceptable yield and price points. The four conceptual design proposals demonstrated a wide range of outcomes, with buildings ranging from 15 to 30 storeys. Daylight Factor (DF), view to the outside, and the avoidance of direct sunlight were the only quantitative and qualitative performance metrics used to implement daylighting to the proposed buildings during the charrette. This paper further assesses the daylighting performance of the four conceptual designs by utilizing Climate-based daylight modeling (CBDM), specifically Daylight Autonomy (DA) and Useful Daylight Illuminance (UDI). Results show that UDI 100-2000lux calculations provide more useful information on the daylighting design than DF. The percentage of the space with a UDI <100-2000lux larger than 50% ranged from 77% to 86% of the time for active occupant behaviour (occupancy from 6am to 6pm). The paper also highlights the architectural features that mostly affect daylighting design in subtropical climates.

Building envelope : performance optimisation processes for a daylight responsive architecture

Traditional shading design principles guide the vertical and horizontal orientation of fins, louvres and awnings being applied to orthogonal planar façades. Due to doubly curved envelopes characterising many contemporary designs, these rules of thumb are now not always applicable. Operable blinds attempt to regulate the fluctuating luminance of daylight and aid in shading direct sunlight. Mostly they remain closed, as workers are commonly too preoccupied to continually adjust them so a reliance on electrically powered lights remains a preference. To remedy these problems, the idea of what it is to sustainable enclose space is reconsidered through the geometric and kinetic optimisation of a parametric skin, with sunlight responsive modules that regulate interior light levels. This research concludes with an optimised design and also defines some unique metrics to gauge the design’s performance in terms of, the amount of exterior unobstructed view, its ability to shade direct sunlight and, its daylight glare probability.

From the editor

In this issue of the Journal, the articles presented to the readers cover the breadth and depth of project management research and practice by addressing the relationship between project strategy and managing projects (Patanakul and Shenhar, “What Project Strategy Really Is: The Fundamental Building Block in Strategic Project Management”), on the need to align corporate strategy with program management (Ritson, Johansen, and Osborne, “Successful Programs Wanted: Exploring the Impact of Alignment”), identifying metrics to measure program success across project contexts (Shao, Müller, and Turner, “Measuring Program Success”), managing individual projects by identifying major risks in customer relationship management (CRM) implementation projects (Papadopoulos, Ojiako, Chipulu, and Lee, “The Criticality of Risk Factors in Customer Relationship Management Projects”), application of earned value management (EVM) to aerospace projects (Kwak and Anbari, “History, Practices, and Future of Earned Value Management in Government: Perspectives From NASA”), and capturing tacit knowledge of construction project professionals to determine the optimal construction site layout (Abdul-Rahman, Wang, and Siong, “Knowledge Acquisition Using Psychotherapy Technique for Critical Factors Influencing Construction Project Layout Planning”)...

Earned value management insights using inferential statistics

Purpose – The purpose of this paper is to summarise a successfully defended doctoral thesis. The main purpose of this paper is to provide a summary of the scope, and main issues raised in the thesis so that readers undertaking studies in the same or connected areas may be aware of current contributions to the topic. The secondary aims are to frame the completed thesis in the context of doctoral-level research in project management as well as offer ideas for further investigation which would serve to extend scientific knowledge on the topic. Design/methodology/approach – Research reported in this paper is based on a quantitative study using inferential statistics aimed at better understanding the actual and potential usage of earned value management (EVM) as applied to external projects under contract. Theories uncovered during the literature review were hypothesized and tested using experiential data collected from 145 EVM practitioners with direct experience on one or more external projects under contract that applied the methodology. Findings – The results of this research suggest that EVM is an effective project management methodology. The principles of EVM were shown to be significant positive predictors of project success on contracted efforts and to be a relatively greater positive predictor of project success when using fixed-price versus cost-plus (CP) type contracts. Moreover, EVM's work-breakdown structure (WBS) utility was shown to positively contribute to the formation of project contracts. The contribution was not significantly different between fixed-price and CP contracted projects, with exceptions in the areas of schedule planning and payment planning. EVM's “S” curve benefited the administration of project contracts. The contribution of the S-curve was not significantly different between fixed-price and CP contracted projects. Furthermore, EVM metrics were shown to also be important contributors to the administration of project contracts. The relative contribution of EVM metrics to projects under fixed-price versus CP contracts was not significantly different, with one exception in the area of evaluating and processing payment requests. Practical implications – These results have important implications for project practitioners, EVM advocates, as well as corporate and governmental policy makers. EVM should be considered for all projects – not only for its positive contribution to project contract development and administration, for its contribution to project success as well, regardless of contract type. Contract type should not be the sole determining factor in the decision whether or not to use EVM. More particularly, the more fixed the contracted project cost, the more the principles of EVM explain the success of the project. The use of EVM mechanics should also be used in all projects regardless of contract type. Payment planning using a WBS should be emphasized in fixed-price contracts using EVM in order to help mitigate performance risk. Schedule planning using a WBS should be emphasized in CP contracts using EVM in order to help mitigate financial risk. Similarly, EVM metrics should be emphasized in fixed-price contracts in evaluating and processing payment requests. Originality/value – This paper provides a summary of cutting-edge research work and a link to the published thesis that researchers can use to help them understand how the research methodology was applied as well as how it can be extended.

Comparison and modification of car following models toward a more accurate microscopic simulation parameters reproduction

Traffic safety studies demand more than what current micro-simulation models can provide as they presume that all drivers of motor vehicles exhibit safe behaviours. Several car-following models are used in various micro-simulation models. This research compares the mainstream car following models’ capabilities of emulating precise driver behaviour parameters such as headways and Time to Collisions. The comparison firstly illustrates which model is more robust in the metric reproduction. Secondly, the study conducted a series of sensitivity tests to further explore the behaviour of each model. Based on the outcome of these two steps exploration of the models, a modified structure and parameters adjustment for each car-following model is proposed to simulate more realistic vehicle movements, particularly headways and Time to Collision, below a certain critical threshold. NGSIM vehicle trajectory data is used to evaluate the modified models performance to assess critical safety events within traffic flow. The simulation tests outcomes indicate that the proposed modified models produce better frequency of critical Time to Collision than the generic models, while the improvement on the headway is not significant. The outcome of this paper facilitates traffic safety assessment using microscopic simulation.

Exploiting SNOMED CT concepts and relationships for clinical information retrieval : Australian e-Health Research Centre and Queensland University of Technology at the TREC 2012 Medical Track

The Australian e-Health Research Centre and Queensland University of Technology recently participated in the TREC 2012 Medical Records Track. This paper reports on our methods, results and experience using an approach that exploits the concept and inter-concept relationships defined in the SNOMED CT medical ontology. Our concept-based approach is intended to overcome specific challenges in searching medical records, namely vocabulary mismatch and granularity mismatch. Queries and documents are transformed from their term-based originals into medical concepts as defined by the SNOMED CT ontology, this is done to tackle vocabulary mismatch. In addition, we make use of the SNOMED CT parent-child `is-a' relationships between concepts to weight documents that contained concept subsumed by the query concepts; this is done to tackle the problem of granularity mismatch. Finally, we experiment with other SNOMED CT relationships besides the is-a relationship to weight concepts related to query concepts. Results show our concept-based approach performed significantly above the median in all four performance metrics. Further improvements are achieved by the incorporation of weighting subsumed concepts, overall leading to improvement above the median of 28% infAP, 10% infNDCG, 12% R-prec and 7% Prec@10. The incorporation of other relations besides is-a demonstrated mixed results, more research is required to determined which SNOMED CT relationships are best employed when weighting related concepts.