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Full-Text Articles in Physical Sciences and Mathematics

Generating A Dynamic Synthetic Population - Using An Age-Structured Two-Sex Model For Household Dynamics, Mohammad-Reza Namazi-Rad, Payam Mokhtarian, Pascal Perez Apr 2014

Generating A Dynamic Synthetic Population - Using An Age-Structured Two-Sex Model For Household Dynamics, Mohammad-Reza Namazi-Rad, Payam Mokhtarian, Pascal Perez

Payam Mokhtarian

Generating a reliable computer-simulated synthetic population is necessary for knowledge processing and decision-making analysis in agent-based systems in order to measure, interpret and describe each target area and the human activity patterns within it. In this paper, both synthetic reconstruction (SR) and combinatorial optimisation (CO) techniques are discussed for generating a reliable synthetic population for a certain geographic region (in Australia) using aggregated- and disaggregated-level information available for such an area. A CO algorithm using the quadratic function of population estimators is presented in this paper in order to generate a synthetic population while considering a two-fold nested structure for …


An Outlier Robust Block Bootstrap For Small Area Estimation, Payam Mokhtarian, Ray Chambers Mar 2014

An Outlier Robust Block Bootstrap For Small Area Estimation, Payam Mokhtarian, Ray Chambers

Payam Mokhtarian

Small area inference based on mixed models, i.e. models that contain both fixed and random effects, are the industry standard for this field, allowing between area heterogeneity to be represented by random area effects. Use of the linear mixed model is ubiquitous in this context, with maximum likelihood, or its close relative, REML, the standard method for estimating the parameters of this model. These parameter estimates, and in particular the resulting predicted values of the random area effects, are then used to construct empirical best linear unbiased predictors (EBLUPs) of the unknown small area means. It is now well known …


A General Framework For Infrastructure System Reliability Modelling And Analysis, Payam Mokhtarian, Mohammad-Reza Namazi-Rad, Tin Kin Ho, Mahmoud Efatmaneshnik Mar 2014

A General Framework For Infrastructure System Reliability Modelling And Analysis, Payam Mokhtarian, Mohammad-Reza Namazi-Rad, Tin Kin Ho, Mahmoud Efatmaneshnik

Payam Mokhtarian

An infrastructure system is inherently complex, with layers of both explicitly defined and hidden or subtle interfaces with other infrastructure systems and human users. High availability is desired, which implies stringent requirements on reliability and safety. Reliability analysis typically starts at component or sub-system level and aggregates through the system functional hierarchy. Because of the system complexity, incorporating occurrences of all possible interactions and scenarios is not always practical and failure data is often limited. Moreover, there are unobserved events among the sub-systems distributing either randomly or with temporal trend. To facilitate reliability analysis amid the complex environment and uncertain …


Punctuality Improvement In Australian Rail Freight Network By Transit Time Management, Hadi Ghaderi, Mohammad-Reza Namazi-Rad, Payam Mokhtarian, Jingang Fei, Stephen Cahoon, Tin Kin Ho Mar 2014

Punctuality Improvement In Australian Rail Freight Network By Transit Time Management, Hadi Ghaderi, Mohammad-Reza Namazi-Rad, Payam Mokhtarian, Jingang Fei, Stephen Cahoon, Tin Kin Ho

Payam Mokhtarian

With rapid development in product globalization and just-in-time production over the last two decades, area-specific reliable, responsive and customer-oriented rail freight services are in demand and are of increasing interest. Having a proper understanding of underlying factors in the evaluation of the quality of rail freight services is a key challenge in the short-term and long-term regional and metropolitan freight mobility planning, particularly within the context of a competitive rail freight market as in Australia. Among the fundamental attributes of rail freight services, transit time and reliability/punctuality are of utmost importance, which also tend to be inevitably correlated. This paper …