Search results for "uncertainty"
showing 10 items of 1010 documents
Fractional Derivatives in Interval Analysis
2017
In this paper, interval fractional derivatives are presented. We consider uncertainty in both the order and the argument of the fractional operator. The approach proposed takes advantage of the property of Fourier and Laplace transforms with respect to the translation operator, in order to first define integral transform of interval functions. Subsequently, the main interval fractional integrals and derivatives, such as the Riemann–Liouville, Caputo, and Riesz, are defined based on their properties with respect to integral transforms. Moreover, uncertain-but-bounded linear fractional dynamical systems, relevant in modeling fractional viscoelasticity, excited by zero-mean stationary Gaussian…
Behavioral and Neural Arguments of Motivational Influence on Decision Making During Uncertainty
2020
The scientific world is increasingly interested in motivation, primarily due to the suspected impact on decision-making abilities, particularly in uncertain conditions. To explore this plausible relationship, 28 healthy participants were included in the study and performed decision-making and motivational tasks while their neural activity was recorded. All participants performed the Iowa Gambling Task (IGT) and were split into two groups based on their score, one favorable group with 14 participants who performed advantageously and one undecided group with 14 participants who failed to develop the correct strategy on the IGT. In addition, all participants performed the Effort Expenditure fo…
A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins
2018
Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The Europea…
Labour Market Uncertainty and Career Perspectives: Competence in Entrepreneurship Courses
2016
Nowadays entrepreneurship is high on the agenda of many countries, and the number of entrepreneurship education initiatives is growing fast. Since the beginning of the third millennium, European Union institutions (European Commission 2003, 2009, 2010, 2013), OECD (2010) and national governments across the European Union have become increasingly involved in entrepreneurship education. The various schemes and initiatives address primarily two broad objectives, on the one hand, supporting new business start-ups and, on the other hand, developing an entrepreneurial mindset in society (and among the young in particular). For example, an international survey conducted by the European Commission …
Dealing with preference uncertainty in contingent willingness to pay for a nature protection program: A new approach
2013
In this paper, we propose an alternative preference uncertainty measurement approach where respondents have the option to indicate their willingness to pay (WTP) for a nature protection program either as exact values or intervals from a payment card, depending on whether they are uncertain about their valuation. On the basis of their responses, we then estimate their degree of uncertainty. New within this study is that the respondent's degree of uncertainty is "revealed", while it is "stated" in those using existing measurement methods. Three statistical models are used to explore the sources of respondent uncertainty. We also present a simple way of calculating the uncertainty adjusted mea…
Performance assessment of water companies: A metafrontier approach accounting for quality of service and group heterogeneities
2021
Abstract The assessment of water companies’ efficiency, productivity and quality of service is part of the process to set water tariffs and therefore, is relevant for regulators and customers. However, the water industry involves several heterogeneous water companies. Following a pioneering approach, this study estimates productivity change and its drivers considering the non-homogeneous nature of the water companies and incorporating quality of service variables as undesirable outputs. In doing so, the metafrontier Malmquist Luenberger productivity index was estimated for a sample of English and Welsh water and sewerage companies (WaSCs) and water only companies (WoCs) over the years 2001–…
Exploring the relationship between Information and Communication Technologies (ICT) and academic performance: A multilevel analysis for Spain
2021
Abstract With the world becoming increasingly digitalized, determining the relationship between the use of Information and Communication Technologies (ICT) and educational outcomes takes on special relevance for guiding educational policy decisions in a reasoned way. The objective of this research is to explore the relationship between different types of ICT use at school and at home, students' attitudes towards ICT, and academic performance, as well as to see if these associations differ according to the level of performance of the students. For this purpose, we apply multilevel regression models and quantile regression models with data from the Programme for International Student assessme…
Macro-uncertainty and financial stress spillovers in the Eurozone
2020
Abstract This paper studies macro-uncertainty and financial distress spillovers within the Eurozone. We propose a novel methodology to derive the indices of spillovers, by using a Global Vector autoregressive model fitted to data sampled at mixed-frequencies. We find that macro-uncertainty and financial stress are relatively disconnected in the Eurozone. We also show that connectedness between core and periphery Eurozone countries mainly operates through financial stress and it decreases since the outbreak of the Eurozone sovereign debt crisis (with an increasing role played by peripheral countries). As a result, investors and policymakers should monitor separately macro-uncertainty and fin…
COVID‐19 and tourism: What can we learn from the past?
2020
Abstract The impact of the COVID‐19 crisis on tourism flows is without precedent in terms of speed and severity. In this paper, we try to infer a possible future scenario for the tourism sector, evaluating the medium‐term effects of past pandemics on tourist arrivals. We find that pandemics lead to a persistent decline in tourist arrivals, with the effects being larger in developing and emerging countries. Interestingly, the effects are heterogeneous across countries and episodes, and depend on several economic conditions such as the overall health system performance, the severity of the shock, and the uncertainty induced by the pandemic event.
A multiple criteria decision model for analyzing and choosing among different development patterns for the Helsinki cargo harbor
1999
Abstract This paper describes a real application of a multicriteria approach to choosing among different options for developing the Helsinki harbor. In addition to the environmental impact assessment procedure, an analysis of the alternatives using the SMAA-method (Stochastic Multiobjective Acceptability Analysis) is carried out. The method applied here has been developed for situations in which the use of decision-makers’ preference information is not possible. Instead, the problem is described by typical weight vectors leading to each solution, taking into account the evident uncertainty embedded in the criteria values.