George Athanasopoulos

Learn More
In many applications, there are multiple time series that are hierarchically organized and can be aggregated at several different levels in groups based on products, geography or some other features. We call these “hierarchical time series”. They are commonly forecast using either a “bottom-up” or a “top-down” method. In this paper we propose a new approach(More)
Scientific WorkFlows (SWFs) need to utilize components and applications in order to satisfy the requirements of specific workflow tasks. Technology trends in software development signify a move from component-based to service-oriented approach, therefore SWF will inevitably need appropriate tools to discover and integrate heterogeneous services. In this(More)
In this paper we explore the hierarchical nature of tourism demand time series and produce short-term forecasts for Australian domestic tourism. The data and forecasts are organized in a hierarchy based on disaggregating the data for different geographical regions and for different purposes of travel. We consider five approaches to hierarchical forecasting:(More)
In this paper, we model and forecast Australian domestic tourism demand. We use a regression framework to estimate important economic relationships for domestic tourism demand. We also identify the impact of world events such as the 2000 Sydney Olympics and the 2002 Bali bombings on Australian domestic tourism. To explore the time series nature of the data,(More)
In this paper we propose a new set of multivariate stochastic models that capture time varying seasonality within the vector innovations structural time series (VISTS) framework. These models encapsulate exponential smoothing methods in a multivariate setting. The models considered are the local level, local trend and damped trend VISTS models with an(More)
BACKGROUND Levosimendan (LS) improves cardiac contractility without increasing myocardial oxygen demand. We administrated LS on a monthly intermittent 24-hour protocol and evaluated the clinical effect after 6 months in a randomized, open, prospective study. METHODS AND RESULTS Fifty patients (age 45-65 years) with LV systolic dysfunction and New York(More)
OBJECTIVE To examine the extent of cardiac muscle and sternocleidomastoid muscle (SCM) involvement detected by MRI measurement of T2 relaxation time in patients with Duchenne muscular dystrophy (DMD) and no cardiorespiratory symptoms. DESIGN Prospective controlled study. SETTING Teaching referral hospital and university hospital. SUBJECTS Seventeen(More)