Search results for "uncertainty."
showing 10 items of 972 documents
GRANULAR-INFORMATION-BASED RISK ANALYSIS IN UNCERTAIN SITUATIONS
2006
In the real life almost all of the decisions that we have to make incorporate uncertainty about the future events. Assessment of the uncertainty and, thus, the risk that is inherent in these decisions models can be critical. It is even truer if we are talking about the possibility of negative impact on the environment. It is very important to assess all the environmental risks in a project if there is any hazard to the environment. In this paper the possibility of using granular information is considered. The main advantage of the granular information is that it can be used to assess risks in situations when information about future events is incomplete and imprecise. Moreover, we can use n…
On overall sampling plan for small area estimation
2017
The time and budget restrictions in survey sampling can impose limits on the area sample sizes. This may reduce the possibility to obtain area-specific and population parameters estimates with adequate precision. Market research companies and institutes for producing official statistics face frequently this problem. Various models and methods for small area estimation (SAE) have been developed to solve this problem. The sample allocation must support the selected model and method to ensure efficient estimation and must be implemented in the design phase of the survey. The proposed allocation is developed by incorporating auxiliary information, a model, and an estimation method. The estimate…
Gaussian processes retrieval of crop traits in Google Earth Engine based on Sentinel-2 top-of-atmosphere data.
2022
The unprecedented availability of optical satellite data in cloud-based computing platforms, such as Google Earth Engine (GEE), opens new possibilities to develop crop trait retrieval models from the local to the planetary scale. Hybrid retrieval models are of interest to run in these platforms as they combine the advantages of physically-based radiative transfer models (RTM) with the flexibility of machine learning regression algorithms. Previous research with GEE primarily relied on processing bottom-of-atmosphere (BOA) reflectance data, which requires atmospheric correction. In the present study, we implemented hybrid models directly into GEE for processing Sentinel-2 (S2) Level-1C (L1C)…
Analysis of parametric uncertainty in a shot noise model
2005
All model calibrations are subject to uncertainty. Even when an optimization procedure is used, the specific calibration period strongly influences the parameter values and causes uncertainty in streamflow prediction. The present paper aims to study the influence that the dimension and the position of the sampling period have on the uncertainty of the response of a daily conceptual shot noise model. The simulations have been conducted using continuous daily series of discharges recorded for 76 years on the river basin of Oreto (Palermo, Italy). Many continuous sub-series for simulations have been obtained from the historical series available. In the first place many model calibrations have …
Testing and implementing a new approach to estimating interregional output multipliers using input-output data for South Korean regions
2020
Flegg's location quotient (FLQ) is a useful tool for estimating intraregional output multipliers. This paper uses it as one component when estimating interregional multipliers. Using statistical information criteria and official data for 16 South Korean regions, it is found that the best approach is to combine the FLQ with a simple trade model. The paper explains how the proposed procedure can be implemented for both multiple and individual regions, and also how a region-specific value for the unknown parameter δ in the FLQ formula can be determined. Finally, an illustrative case study of one of the regions is carried out.
Virtualization of work in global supply chains
2016
ABSTRACT. Background: The paper is devoted to the notion and benefits of implementing virtual work in global supply chains. Virtual work must be understood as an intentional activity of a human being, aimed at rendering services (tangible and intangible), by means of ITC tools, performed in a distance from the traditional place of work, in a mobile manner. The empirical research were conducted on the basis of 4 case studies of global leaders of supply chains, which in accordance with M. Fisher's classification, represent two types. The case studies confirmed the positive influence of virtual work both in effective and flexible supply chains. Favourable market and technological conditions an…
Uncertainty analysis and symmetry restoration in nuclear self-consistent methods
2015
This thesis contains two articles, in the following denoted by I and II, and an introduction to them. In Chapter 1, I present the theoretical models of nuclear structure. In Chapter 2, I introduce the basic ideas about the density functional theory (DFT) and self-consistent mean-field (SCMF) calculations. In Chapter 3, I give the formulae for the uncertainty propagation, which is the error analysis method used in article I. As a proper tool to survey the predictive power of theoretical models, the error analysis now has become more and more widely used. By analyzing the propagation of uncertainties, one tries to find out the e ectiveness of the calculation with a given parameter set obtaine…
More educated, more mobile? Evidence from post-secondary education reform
2016
More educated, more mobile? Evidence from post-secondary education reform. Spatial Economic Analysis. This paper examines the causal impact of the level of education on within-country migration. To account for biases resulting from selection into post-secondary education, it uses a large-scale reform within the higher education system that gradually transformed former vocational colleges into polytechnics in Finland in the 1990s. This reform created quasi-exogenous variation in the supply of higher education over time and across regions. The results based on multinomial treatment effects models and population register data show that, overall, polytechnic graduates have a significantly highe…
Does corn market uncertainty impact the US ethanol prices?
2018
The growing interest in biofuel as a green energy source has intensified the linkages between corn and ethanol markets, especially in the United States that represents the largest producing and exporting country for ethanol in the world. In this study, we examine the effect of corn market uncertainty on the price changes of US ethanol applying a set of GARCH-jump models. We find that the US ethanol price changes react positively to the corn market volatility shocks after controlling for the effect of oil price uncertainty. In addition, we document that the impact of corn price volatility on the US ethanol prices appears to be asymmetric. Specifically, only the positive corn market volatilit…
La spatialité des dommages et risques environnementaux comme point de convergence entre géographie, écologie et politique
2012
The analysis of complex systems such as those captured by scientific ecology shows that the occurrence of damaging events is difficult to predict. Moreover, most of these unpredictable events will be those with the strongest echoes, giving full meaning to the concept of risk as cross between hazard and vulnerability. Each of these two components of risk has a spatial dimension more or less obvious, and to understand the natural risk, occurrence and spatial extension of the hazard and the vulnerability should be analyzed jointly. Thus, we show that for environmental risk, the question of "where?" posed by the prediction refers certainly to ecological and geographical problems, but also econo…