Search results for "Uncertainty"
showing 10 items of 1010 documents
DYNAMIC SEMANTIC USER PROFILING FROM IMPLICIT WEB NAVIGATION DATA
2014
International audience; On the Web, pages are often dynamically generated and allow publishers to individually adapt contents to each viewer. Underlying systems must correctly understand the user's context - crucial especially in the case of online advertisement placement. The article at hand describes our proposition of a novel profiling system, adapted to the special needs of digital advertising. Based on Semantic Web Technologies, the MindMinings system relies on an ontology to enable thorough understanding of each user's context and needs. The underlying ontology structure also provides enhanced interoperability with semantically annotated knowledge resources, notably vocabularies from …
Uncertainty in information system development: Causes, effects, and coping mechanisms
2020
Information system development (ISD) projects are an ever-growing field of project management (PM) with their unique features, and project failures in ISD are relatively common. In the broader context of PM, uncertainty is a studied, yet mercurial phenomenon. By contrast, uncertainty in ISD projects has received relatively little attention from scholars, and PM literature has not systematically focused on uncertainty in ISD from a viewpoint other than that of project managers. In order to understand uncertainties in ISD projects, we need to first understand the causes behind them, their effects on everyday ISD work, and share coping mechanisms utilized among industry professionals. In the c…
A fuzzy framework to evaluate service quality in the healthcare industry: An empirical case of public hospital service evaluation in Sicily
2016
A novel fuzzy framework is considered to analyze healthcare service quality.The fundamental quality structure of healthcare service delivered in Sicily is described.The public healthcare in Sicily (Italy) is strategically analyzed.Strategic stakeholders' oriented implications for healthcare improvements are given. A novel fuzzy evaluation framework is applied in this study to evaluate service quality in the public healthcare sector. In particular, the proposed framework is based on the ServQual disconfirmation paradigm and incorporates the Analytic Hierarchy Process (AHP) method to elicit reliable estimations of service quality expectations. Moreover, degrees of uncertainty, subjectivity an…
Weak convergence to the coalescent in neutral population models
1999
For a large class of neutral population models the asymptotics of the ancestral structure of a sample of n individuals (or genes) is studied, if the total population size becomes large. Under certain conditions and under a well-known time-scaling, which can be expressed in terms of the coalescence probabilities, weak convergence in D E ([0,∞)) to the coalescent holds. Further the convergence behaviour of the jump chain of the ancestral process is studied. The results are used to approximate probabilities which are of certain interest in applications, for example hitting probabilities.
Uncertainty analysis of life cycle assessment of asphalt surfacings
2023
The Life Cycle Assessment (LCA) of asphalt pavements are associated with significant uncertainty resulting from variability in the quantity and impact of individual components, the quality of data for each component, and variability of asphalt durability. This study presents a framework to quantify and incorporate the uncertainty of LCA and asphalt durability data into LCA of asphalt surfacings. The suggested framework includes: estimating the uncertainty of asphalt production processes by the pedigree matrix method, conducting a deterministic LCA, applying Monte Carlo Simulation (MCS) to estimate the probability density functions (PDFs) of the considered impacts using the uncertainty data,…
The effect of the emotive decisions in prospect theory.
2015
AbstractThe main purpose of this paper was to show that the certainty and reflection effects of prospect theory do not occur when stimuli have an affective value. To this end, 160 participants were asked to reply to a series of problems originally designed by Kahneman and Tversky (1979), but modified according to the contributions of Rottenstreich and Hsee (2001). The sample was divided into four experimental conditions, two in a gain situation and two in a loss situation. In both cases, affect-rich and affect-poor stimuli were applied in sure and probable alternatives. The findings showed that, in agreement with our hypotheses, the affective value of the stimuli altered the outcome predict…
Simulating term structure of interest rates with arbitrary marginals
2011
Decision models under uncertainty rely their analysis on scenarios of the economic factors. A key economic factor is the term structure of interest rates (yields). Simulation models of the yield curve usually assume that the conjugate distribution of the interest rates is lognormal. Dynamic models, like vector auto-regression, implicitly postulate that the logarithm of the interest rates is normally distributed. Statistical analyses have, however, shown that stationary transformations (yield changes) of the interest rates are substantially leptokurtic, thus posing serious doubts on the reliability of the available models. We propose in this paper a VARTA model (Biller and Nelson, 2003) to s…
Prevalence of unwillingness and uncertainty to vaccinate against COVID-19 in older people: A systematic review and meta-analysis.
2021
The coronavirus disease 2019 (COVID-19) has been shown to have more severe health outcomes in older people specifically in relation to mortality and disability. Vaccination seems to be efficacious and safe for preventing the negative consequences of COVID-19, but vaccine hesitancy seems to be high in older adults. We therefore aimed to investigate the prevalence of unwillingness and the uncertainty to vaccinate against COVID-19 in older people and the factors that can be associated with the unwillingness to vaccinate. For this work, we searched several databases until 18th June 2021 for studies reporting the prevalence of unwillingness and the uncertainty to vaccinate against COVID-19 in pe…
Robust control of continuous-time systems with state-dependent uncertainties and its application to electronic circuits
2014
In this paper, the problems of robust stability and stabilization are investigated for a class of continuous-time uncertain systems. The uncertainties in the model are state-dependent and belong to a polytopic convex set, as can be found in many electronic circuits and some other applications. The global asymptotic stability conditions for such systems are first established by the classic common quadratic Lyapunov function approach. To reduce conservativeness, a particular class of nonquadratic parameter-dependent Lyapunov functions is introduced, by which improved robust stability conditions for the underlying systems are also derived. Based on the stability criteria, a static output feedb…
Quantifying uncertainty in high resolution biophysical variable retrieval with machine learning
2022
The estimation of biophysical variables is at the core of remote sensing science, allowing a close monitoring of crops and forests. Deriving temporally resolved and spatially explicit maps of parameters of interest has been the subject of intense research. However, deriving products from optical sensors is typically hampered by cloud contamination and the trade-off between spatial and temporal resolutions. In this work we rely on the HIghly Scalable Temporal Adaptive Reflectance Fusion Model (HISTARFM) algorithm to generate long gap-free time series of Landsat surface reflectance data by fusing MODIS and Landsat reflectances. An artificial neural network is trained on PROSAIL inversion to p…