Empirical evaluation of public transport travel time variability

Although transit travel time variability is essential for understanding the deterioration of reliability, optimising transit schedule and route choice; it has not attracted enough attention from the literature. This paper proposes public transport-oriented definitions of travel time variability and explores the distributions of public transport travel time using the Transit Signal Priority data. First, definitions of public transport travel time variability are established by extending the common definitions of variability in the literature and by using route and services data of public transport vehicles. Second, the paper explores the distribution of public transport travel time. A new approach for analysing the distributions involving all transit vehicles as well as vehicles from a specific route is proposed. The Lognormal distribution is revealed as the descriptors for public transport travel time from the same route and service. The methods described in this study could be of interest for both traffic managers and transit operators for planning and managing the transit systems.

Development and validation of an instrument to measure organizational cultures' support of business process management

The purpose of Business Process Management (BPM) is to increase the efficiency and effectiveness of organizational processes through improvement and innovation. Despite a common understanding that culture is an important element in these efforts, there is a dearth of theoretical and empirical research on culture as a facilitator of successful BPM. We develop the BPM culture construct and propose a validated instrument with which to measure organizational cultures’ support of BPM. The operationalization of the BPM culture concept provides a theoretical foundation for future research and a tool to assist organizations in developing a cultural environment that supports successful BPM.

Empirical evaluation of brisbane macroscopic fundamental diagram

The Macroscopic Fundamental Diagram (MFD) relates space-mean density and flow, and the existence with dynamic features was confirmed in congested urban network with real data set from loop detectors and taxi probes. Since the MFD represents the area-wide network traffic performances, it gives foundations for perimeter control strategies and an area traffic state estimation enabling area-based network control. However, limited works have been reported on real world example from signalised arterial network. This paper fuses data from multiple sources (Bluetooth, Loops and Signals) and develops a framework for the development of the MFD for Brisbane. Existence of the MFD in Brisbane network is confirmed. Different MFDs (from whole network and several sub regions) are evaluated to discover the spatial partitioning in network performance representation.

An introduction to the application of (case 1) best–worst scaling in marketing research

We review and discuss recent developments in best–worst scaling (BWS) that allow researchers to measure items or objects on measurement scales with known properties. We note that BWS has some distinct advantages compared with other measurement approaches, such as category rating scales or paired comparisons. We demonstrate how to use BWS to measure subjective quantities in two different empirical examples. One of these measures preferences for weekend getaways and requires comparing relatively few objects; a second measures academics' perceptions of the quality of academic marketing journals and requires comparing a significantly large set of objects. We conclude by discussing some limitations and future research opportunities related to BWS.

Residential dissonance and mode choice

Residential dissonance refers to the mismatch in land-use patterns between individuals’ preferred residential neighbourhood type and the type of neighbourhood in which they currently reside. Current knowledge regarding the impact of residential dissonance is limited to short-term travel behaviours in urban vs. suburban, and rural vs. urban areas. Although the prevailing view is that dissonants adjust their orientation and lifestyle around their surrounding land use over time, empirical evidence is lacking to support this proposition. This research identifies both short-term mode choice behaviour and medium-term mode shift behaviour of dissonants in transit oriented development (TODs) vs. non-TOD areas in Brisbane, Australia. Natural groupings of neighbourhood profiles (e.g. residential density, land use diversity, intersection density, cul-de-sac density, and public transport accessibility levels) of 3957 individuals were identified as living either in a TOD (510 individuals) or non-TOD (3447 individuals) areas in Brisbane using the TwoStep cluster analysis technique. Levels of dissonance were measured based on a factor analysis of 16 items representing the travel attitudes/preferences of individuals. Two multinomial logistic (MNL) regression models were estimated to understand mode choice behaviour of (1) TOD dissonants, and (2) non-TOD dissonants in 2009, controlling for socio-demographics and environmental characteristics. Two additional MNL regression models were estimated to investigate mode shift behaviour of (3) TOD dissonants, and (4) non-TOD dissonants between 2009 and 2011, also controlling for socio-demographic, changes in socio-demographic, and built environmental factors. The findings suggest that travel preference is relatively more influential in transport mode choice decisions compared with built environment features. Little behavioural evidence was found to support the adjustment of a dissonant orientation toward a particular land use feature and mode accessibility they represent (e.g. a modal shift to greater use of the car for non-TOD dissonants). TOD policies should focus on reducing the level of dissonance in TODs in order to enhance transit ridership.

Reply to comment on “Characterising metal build-up on urban road surfaces” by Egodawatta et al. (2013)

In the recent manuscript published by Egodawatta et al. (2013), the authors investigated the build-up process of heavy metals (HMs) associated with road-deposited sediment (RDS) on residential road surfaces, and presented empirical models for the prediction of both the surface loads and build-up rates of HMs on these surfaces...

Knowledge governance in project-based organizations : theoretical and empirical approaches

This paper conceptualizes knowledge governance (KG) in project-based organizations (PBOs) and its methodological approaches for empirical investigation. Three key contributions towards a multi-faceted view of KG and an understanding of KG in PBOs are advanced. These contributions include a definition of KG in PBOs, a conceptual framework to investigate KG and a methodological framework for empirical inquiry into KG in PBO settings. Our definition highlights the contingent nature of KG processes in relation to their organizational context. The conceptual framework addresses macro- and micro-level elements of KG and their interaction. The methodological framework proposes five different research approaches, structured by differentiation and integration of various ontological and epistemological stances. Together these contributions provide a novel platform for understanding KG in PBOs and developing new insights into the design and execution of research on KG within PBOs.

Knowledge management in criminal investigation : empirical examination and re-conceptualisation of dean's investigative thinking styles

This thesis explored the current state of knowledge management in policing. A psychometric instrument was created and validated for use within police agencies as a means of facilitating the capture and transferral of critical investigative knowledge. The aim is to ensure that investigative expertise is not lost when detectives retire or leave the service. Improved knowledge management strategies that rely on this psychometric instrument can lead to greater efficiency and effectiveness in criminal investigation.

The value of health and wellbeing : an empirical model of value creation in social marketing

Purpose The purpose of this paper is to investigate the role of multiple actors in the value creation process for a preventative health service, and observe the subsequent impact on key service outcomes of satisfaction and customer behaviour intentions to use a preventative health service again in the future. Design/methodology/approach An online self-completion survey of Australian women (n=797) was conducted to test the proposed framework in the context of a free, government-provided breastscreening service. Data were analysed using Structural Equation Modelling (SEM). Findings The findings indicate that functional and emotional value are created from organisational and customer resources. These findings indicate that health service providers and customers are jointly responsible for the successful creation of value, leading to desirable outcomes for all stakeholders. Practical implications The results highlight to health professionals the aspects of service that can be managed in order to create value with target audiences. The findings also indicate the importance of the resources provided by users in the creation of value, signifying the importance of customer education and management. Originality/value This study provides a significant contribution to social marketing through the provision of an empirically validated model of value creation in a preventative health service. The model demonstrates how the creation and provision of value can lead to the achievement of desirable social behaviours - a key aim of social marketing.

Structural characterization and vibrational spectroscopy of the arsenate mineral wendwilsonite

In this paper, we have investigated on the natural wendwilsonite mineral with the formulae Ca2(Mg,Co)(AsO4)2⋅2(H2O). Raman spectroscopy complimented with infrared spectroscopy has been used to determine the molecular structure of the wendwilsonite arsenate mineral. A comparison is made with the roselite mineral group with formula Ca2B(AsO4)2⋅2H2O (where B may be Co, Fe2+, Mg, Mn, Ni, Zn). The Raman spectra of the arsenate related to tetrahedral arsenate clusters with stretching region shows strong differences between that of wendwilsonite and the roselite arsenate minerals which is attributed to the cation substitution for calcium in the structure. The Raman arsenate (AsO4)3− stretching region shows strong differences between that of wendwilsonite and the roselite arsenate minerals which is attributed to the cation substitution for calcium in the structure. In the infrared spectra complexity exists of multiple to tetrahedral (AsO4)3− clusters with antisymmetric stretching vibrations observed indicating a reduction of the tetrahedral symmetry. This loss of degeneracy is also reflected in the bending modes. Strong Raman bands around 450 cm−1 are assigned to ν4 bending modes. Multiple bands in the 350–300 cm−1 region assigned to ν2 bending modes provide evidence of symmetry reduction of the arsenate anion. Three broad bands for wendwilsonite found at 3332, 3119 and 3001 cm−1 are assigned to OH stretching bands. By using a Libowitzky empirical equation, hydrogen bond distances of 2.65 and 2.75 Å are estimated. Vibrational spectra enable the molecular structure of the wendwilsonite mineral to be determined and whilst similarities exist in the spectral patterns with the roselite mineral group, sufficient differences exist to be able to determine the identification of the minerals.

An IEEE 802.11p empirical performance model for cooperative systems applications

IEEE 802.11p is the new standard for Inter-Vehicular Communications (IVC) using the 5.9 GHz frequency band, as part of the DSRC framework; it will enable applications based on Cooperative Systems. Simulation is widely used to estimate or verify the potential benefits of such cooperative applications, notably in terms of safety for the drivers. We have developed a performance model for 802.11p that can be used by simulations of cooperative applications (e.g. collision avoidance) without requiring intricate models of the whole IVC stack. Instead, it provide a a straightforward yet realistic modelisation of IVC performance. Our model uses data from extensive field trials to infer the correlation between speed, distance and performance metrics such as maximum range, latency and frame loss. Then, we improve this model to limit the number of profiles that have to be generated when there are more than a few couples of emitter-receptor in a given location. Our model generates realistic performance for rural or suburban environments among small groups of IVC-equipped vehicles and road side units.

Volatility timing : how best to forecast portfolio exposures

This paper investigates how best to forecast optimal portfolio weights in the context of a volatility timing strategy. It measures the economic value of a number of methods for forming optimal portfolios on the basis of realized volatility. These include the traditional econometric approach of forming portfolios from forecasts of the covariance matrix, and a novel method, where a time series of optimal portfolio weights are constructed from observed realized volatility and directly forecast. The approach proposed here of directly forecasting portfolio weights shows a great deal of merit. Resulting portfolios are of equivalent economic benefit to a number of competing approaches and are more stable across time. These findings have obvious implications for the manner in which volatility timing is undertaken in a portfolio allocation context.

Observation of ions and particles near busy roads using a Neutral Cluster and Air Ion Spectrometer (NAIS)

Motor vehicles emit large quantities of ions in the form of both charged particles and molecular cluster ions. While, the health effects of inhalation of charged particles is largely unexplored, the concentrations near busy roads and the distance to which these particles and ions are carried have important implications for the exposure of the large percentage of the population that lives close to such roadways. We measured ion concentrations using a neutral cluster and air ion spectrometer (NAIS) near seven busy roads carrying on the average approximately 7000 vehicles hr-1 including about 15% heavy duty diesel vehicles. In this study, charged particle concentrations were measured as a function of downwind distance from the road for the first time. We show that, at a moderate wind speed of 2.0 m s-1, mean charged particle concentrations at the kerb were of the order of 2x104 cm-3 and, more importantly, decreased as d 0.6 where d is the distance from the road. While cluster ions were rapidly depleted by attachment to particles and were not carried to more than about 20 m from the road, elevated concentrations of charged particle were detected up to at least 400 m from the road. Most of the charge on the downwind side was carried on the larger particles, with no excess charge on particles smaller than about 10 nm. At 30 nm, particles carried more than double the charge they would normally carry in equilibrium. There are very few measurements of ions near road traffic and this is the first study of the spatial dispersion of charged particles from a road.

Spreading peak demand for urban rail transit through differential fare policy : a review of empirical evidence

More evenly spread demand for public transport throughout a day can reduce transit service provider‟s total asset and labour costs. A plausible peak spreading strategy is to increase peak fare and/or to reduce off-peak fare. This paper reviews relevant empirical studies for urban rail systems, as rail transit plays a key role in Australian urban passenger transport and experiences severe peak loading variability. The literature is categorised into four groups: a) passenger opinions on willingness to change time for travel, b) valuations of displacement time using stated preference technique, c) simulations of peak spreading based on trip scheduling models, and: d) real-world cases of peak spreading using differential fare. Policy prescription is advised to take into account impacts of traveller‟s time flexibility and joint effects of mode shifting and peak spreading. Although focusing on urban rail, arguments in this paper are relevant to public transport in general with values to researchers and practitioners.

Shrinkage empirical likelihood estimator in longitudinal analysis with time-dependent covariates-application to modeling the health of Filipino children

The method of generalized estimating equations (GEE) is a popular tool for analysing longitudinal (panel) data. Often, the covariates collected are time-dependent in nature, for example, age, relapse status, monthly income. When using GEE to analyse longitudinal data with time-dependent covariates, crucial assumptions about the covariates are necessary for valid inferences to be drawn. When those assumptions do not hold or cannot be verified, Pepe and Anderson (1994, Communications in Statistics, Simulations and Computation 23, 939–951) advocated using an independence working correlation assumption in the GEE model as a robust approach. However, using GEE with the independence correlation assumption may lead to significant efficiency loss (Fitzmaurice, 1995, Biometrics 51, 309–317). In this article, we propose a method that extracts additional information from the estimating equations that are excluded by the independence assumption. The method always includes the estimating equations under the independence assumption and the contribution from the remaining estimating equations is weighted according to the likelihood of each equation being a consistent estimating equation and the information it carries. We apply the method to a longitudinal study of the health of a group of Filipino children.