Search results for " forecast"
showing 10 items of 220 documents
Do different models induce changes in mortality indicators? That is a key question for extending the Lee-Carter model
2021
[EN] The parametric model introduced by Lee and Carter in 1992 for modeling mortality rates in the USA was a seminal development in forecasting life expectancies and has been widely used since then. Different extensions of this model, using different hypotheses about the data, constraints on the parameters, and appropriate methods have led to improvements in the model's fit to historical data and the model's forecasting of the future. This paper's main objective is to evaluate if differences between models are reflected in different mortality indicators' forecasts. To this end, nine sets of indicator predictions were generated by crossing three models and three block-bootstrap samples with …
Uncertainty in water quality modelling: The applicability of Variance Decomposition Approach
2010
Quantification of uncertainty is of paramount interest in integrated urban drainage water quality modelling. Indeed, the assessment of the reliability of the results of complex water quality models is crucial in understanding their significance. However, the state of knowledge regarding uncertainties in urban drainage models is poor. In the case of integrated urban drainage water quality models, due to the fact that integrated approaches are basically a cascade of sub-models (simulating the sewer system, wastewater treatment plant and receiving water body), uncertainty produced in one sub-model propagates to the following ones in a manner dependent on the model structure, the estimation of …
Combining a data-driven approach with seasonal forecasts data to predicting reservoir water volume in the Mediterranean area.
2021
<p>Artificial reservoirs are one of the main water supply resources in the Mediterranean areas; their management can be strongly affected by the problems of drought and water scarcity. The reservoir water level is the result of the hydrological processes occurring in the upstream catchment, which, in turn, depend on meteorological variables, such as rainfall and temperature. It follows that a reliable forecast model of the meteorological forcing, along with a reliable water balance model, could enhance the correct management of a reservoir. With regard to the rainfall/temperature forecast model, the use of forecast climate data in the mid-term may provide further support for t…
Effects of initialization on response of a fully-distributed hydrologic model
2008
Summary Knowledge of initial conditions is very important to correctly model the basin response at the storm event scale. Of particular interest is the influence of topography and soil type on the principal hydrologic variables and runoff generation mechanisms as a function of antecedent wetness conditions. This study addresses the influence of initial states on the short-term hydrologic response and characterizes the effects of topography and soils on the dissipation of the influence of the initialization conditions. Two case studies are considered: a synthetic two-dimensional planar hillslope with various assumed slope magnitudes and soil types; and a real basin (∼800 km2) with actual lan…
A copula-based approach for assessing flood protection overtopping associated with a seasonal flood forecast in Niamey, West Africa
2016
Flood is one of the most important natural disasters that cause huge loss of life and properties every year around the world. Moreover, the International Federation of the Red Cross and Red Crescent Societies pointed out that floods were by far the greatest cause of homelessness. In West Africa, many countries are damaged from flooding almost every season. Thus, this study aimed to set a seasonal flood forecast model and carried out an evaluation of the level of risk associated with each seasonal forecast. HEC-RAS (Hydrologic Engineering Centers River Analysis System) was used to develop a hydro-dynamical model of Niger river on a 160km reach (80km upstream to 80kmdownstream of Niamey), the…
Inflation anchoring and growth: The role of credit constraints
2022
Abstract Can inflation anchoring foster growth? To answer this question, we use panel data on sectoral growth for 22 manufacturing industries from 39 advanced and emerging market economies over 1990–2014 and employ a difference-in-differences strategy based on the theoretical prediction that higher inflation uncertainty particularly depresses investment in industries that are more credit constrained. Industries characterized by high external financial dependence, liquidity needs, and R&D intensity, and low asset tangibility, tend to grow faster in countries with well-anchored inflation expectations. The results, based on an IV approach—using indicators of monetary policy transparency and ce…
Optimizing the level of service quality of a bike-sharing system
2016
Public bike-sharing programs have been deployed in hundreds of cities worldwide, improving mobility in a socially equitable and environmentally sustainable way. However, the quality of the service is drastically affected by imbalances in the distribution of bicycles among stations. We address this problem in two stages. First, we estimate the unsatisfied demand (lack of free lockers or lack of bicycles) at each station for a given time period in the future and for each possible number of bicycles at the beginning of the period. In a second stage, we use these estimates to guide our redistribution algorithms. Computational results using real data from the bike-sharing system in Palma de Mall…
Does the interaction between the accounting method choice and disclosure affect financial analysts’ information environment? The case of joint ventur…
2017
IAS 31 allowed firms to choose between proportionate consolidation and the equity method to record joint ventures in the consolidated accounts of the venturer. Moreover, this election implied a decision about including information in the primary financial statements or in the notes. This paper investigates if financial analysts perceive accounting information differently depending on the method chosen conditioned to the disclosure of the required information in the notes. We analysed a sample of Spanish firms during 2005–2010. We not only considered earnings forecasts, but also examined target prices and stock recommendations. Furthemore, we look at how this accounting choice affects analys…
Tension in the data environment: How organisations can meet the challenge
2022
Big Data is becoming ubiquitous - widely applied across organisations, industry sectors and society. However, the opportunities and risks it presents are not yet fully understood. In this paper we identify and explore the tensions that Big Data can create at multiple levels, focusing on the need for organisations to meet the challenges that can arise. We draw on insights from twelve papers published in the Special Issue of Technological Forecasting & Social Change entitled “Tension in the Data Environment: Can Organisations Meet the Challenge?” in order to build a ‘Multi-Layer Tensions Model’ that highlights key pressures and challenges in the BD environment. We find evidence of tensions of…
Simulation of surface energy fluxes and meteorological variables using the Regional Atmospheric Modeling System (RAMS): Evaluating the impact of land…
2018
Atmospheric mesoscale numerical models are commonly used not only for research and air quality studies, but also for other related applications, such as short-term weather forecasting for atmospheric, hydrological, agricultural and ecological modelling. A key element to produce faithful simulations is the proper representation of the soil parameters used in the initialization of the corresponding mesoscale numerical model. The Regional Atmospheric Modeling System (RAMS) is used in the current study. The model code has been updated in order to permit the model to be initialized using a heterogeneous soil moisture and temperature distribution derived from land surface models. Particularly, RA…