Search results for " Estimation"
showing 10 items of 562 documents
“Living in Contaminated Areas”—Consideration of Different Perspectives
2020
Following large-scale nuclear power plant accidents such as those that occurred at Chernobyl (Ukraine) in 1986 and Fukushima Daiichi (Japan) in 2011, large populations are living in areas containing residual amounts of radioactivity. As a key session of the ConRad conference, experts were invited from different disciplines to provide state-of-the-art information on the topic of "living in contaminated areas." These experts provided their different perspectives on a range of topics including radiation protection principles and dose criteria, environmental measurements and dose estimation, maintaining decent living and working conditions, evidence of health risks, and social impact and risk c…
Experimental P-T-ro Measurements of Supercritical Mixtures of Carbon Dioxide, Carbon Monoxide, and Hydrogen and Semiquantitative Estimation of Their …
2007
The P-T-ρ behavior of the CO2-CO-H2 system was studied in the supercritical region under operative conditions close to those adopted to perform hydrogenation and hydroformylation reactions in dense CO 2, thus providing new interesting information on this fluid mixture. Experiments were performed in a fixed volume reactor in the temperature range from 298 K to 343 K changing the density and the composition of the fluid phase. The one-component (Hildebrand) solubility parameter of the mixture was estimated from experimentally measured P vs T profiles, and its dependence on the density and composition of the system was analyzed to study the antisolvent effect of the permanent gases. We have fo…
Estimation de la relation de salaires de Mincer : choix de specification et enjeux économétriques
2012
In the present doctoral thesis, we estimated Mincer’s (1974) semi logarithmic wage function for the French and Pakistani labour force data. This model is considered as a standard tool in order to estimate the relationship between earnings/wages and different contributory factors. Despite of its vide and extensive use, simple estimation of the Mincerian model is biased because of different econometric problems. The main sources of bias noted in the literature are endogeneity of schooling, measurement error, and sample selectivity. We have tackled the endogeneity and measurement error biases via instrumental variables two stage least squares approach for which we have proposed two new instrum…
Orthogonal Multicarrier Transmission with Modal Channel Estimation
2009
A novel multi-carrier orthogonal transmission scheme is presented. While being simpler to implement, it has a spectral efficiency and design parameters similar to those of Orthogonal Frequency Division Multiplexing based on Offset Quadrature Amplitude Modulation (OFDM/OQAM). A parametric channel estimation technique is subsequently reported. The proposed technique is based on an algorithm obtained from classic Multiple Signal Classification (MUSIC) by relaxation of the hypothesis on the number of measurements with respect to the number of sensors. Numerical simulations show that our proposal outperforms previous works in this field.
Assistive robotic walker parameter identification for estimation of human thrust without force sensors
2017
In this paper we propose a parameter identification procedure for the wheel-motor dynamic of a robotic walker, i.e. a commercial trolley for elderly people endowed with cognitive, sensing and guidance capabilities. The objective of the wheel-motor dynamic model is to generate a suitable time reference to be used in an estimation algorithm. The ultimate goal of the estimation algorithm is to retrieve the thrust, i.e. torque and force, that the older adult user of the robotic walker applies to the platform. These quantities are of paramount importance in order to adopt intelligent and comfortable walker guidance algorithms. The novelty of this approach is the avoidance of additional costly se…
Time estimation and aging: a comparison between young and elderly adults.
2001
Studies about effects of aging on the estimation of short temporal intervals are not conclusive. The aim of the present research was to evaluate age-related differences in the reproduction of a short interval (10 s) using a computerized method. The sample comprised thirteen young adults ( M = 26.15 years) and twelve elderly adults ( M = 79.1 years). Three parameters of time estimation were measured: estimated time, absolute error, and standard deviation. Results showed that time estimates performed by elderly participants were shorter than those of younger ones, although there were no significant differences between the two age groups in the percentage of absolute errors or standard deviat…
Back-Propagation Artificial Neural Network for ERP Adoption Cost Estimation
2011
Published version of a chapter in the book: Enterprise information systems, vol 220, part 2, 180-187. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-642-24355-4_19 Small and medium size enterprises (SMEs) are greatly affected by cost escalations and overruns Reliable cost factors estimation and management is a key for the success of Enterprise Resource Planning (ERP) systems adoptions in enterprises generally and SMEs specifically. This research area is still immature and needs a considerable amount of research to seek solid and realistic cost factors estimation. Majority of research in this area targets the enhancement of estimates calculated by COCOMO family models.…
Labor productivity and firm-level TFP with technology-specific production functions
2020
Abstract We investigate the technological dimension of productivity, presenting an empirical methodology based on mixture models to disentangle the labor productivity differences associated with the firm's choice of technology (BTFP) and those related to the firm's ability to exploit the adopted technology (WTFP). The estimation endogenously determines the number of technologies (in the sector) and degree of technology sharing across firms (i.e., for each firm, the probability of using a given technology). By using comparable data for about 35,000 firms worldwide distributed across 22 (two-digit) sectors, we show BTFP to be at least as important as WTFP in explaining the labor productivity …
Unsteady State Water Level Analysis for Discharge Hydrograph Estimation in Rivers with Torrential Regime: The Case Study of the February 2016 Flood E…
2017
Discharge hydrograph estimation during floods, in rivers with torrential regime, is often based on the use of rating curves extrapolated from very low stage-discharge measurements. To get a more reliable estimation, a reverse flow routing problem is solved using water level data measured in two gauged stations several kilometers from each other. Validation of the previous analysis carried out on the flood event of February 2016 at the Europa Bridge and Castiglione Scalo sections of the Crati River (Cosenza, Italy) is based on the use of 'soft' discharge measurement data and the comparison of the water level data computed in the downstream gauged section by three different hydraulic models w…
A computational proposal for a robust estimation of the Pareto tail index: An application to emerging markets
2022
Abstract In this work, we backtest and compare, under the VaR risk measure, the fitting performances of three classes of density distributions (Gaussian, Stable and Pareto) with respect to three different types of emerging markets: Egypt, Qatar and Mexico. We also propose a new technique for the estimation of the Pareto tail index by means of the Threshold Accepting (TAVaR) and the Hybrid Particle Swarm Optimization algorithm (H-PSOVaR). Furthermore, we test the accuracy and robustness of our estimates demonstrating the effectiveness of the proposed approach.