Search results for " Opera"
showing 10 items of 3606 documents
Sharing economy and incumbents' pricing strategy: The impact of Airbnb on the hospitality industry
2019
Abstract In this paper, we examine how the emergence of sharing economy platforms influences incumbents' price responses. Grounding on the literature on price reactions to new entrants and on the unique characteristics of the sharing economy, we argue that the effect of the penetration of the sharing economy on incumbents' prices is not straightforward, and actually depends on the type of incumbents as well as certain product/service offer characteristics. Indeed, relying on a large sample of hotel price offerings from the Italian market, we find that the effect of the growing relevance of the sharing economy (exemplified by Airbnb) on incumbents' prices depends on the type of incumbents (l…
La filiera siciliana della pasta: un'applicazione della netchain analysis
2016
The system of Sicilian durum wheat is facing, as indeed is happening to the entire food system, the evolution of consumption patterns toward higher quality requirements: health-wise, primarily, but also including some intangible requirements. Recent acquisitions in the field of healthy food, have called attention to some specific characteristics of Sicilian durum wheat. The durum wheat sector represents a major landmark for regional agriculture, being by far the most widespread arable crop in Sicily; a crop that, over the past 30 years, has evolved considerably, due to the impact of EU regulations. Currently, the whole Sicilian cereal-pasta chain shows shortcomings in organization and size,…
Do commodity assets hedge uncertainties? What we learn from the recent turbulence period?
2022
AbstractThis study analyses the impact of different uncertainties on commodity markets to assess commodity markets' hedging or safe-haven properties. Using time-varying dynamic conditional correlation and wavelet-based Quantile-on-Quantile regression models, our findings show that, both before and during the COVID-19 crisis, soybeans and clean energy stocks offer strong safe-haven opportunities against cryptocurrency price uncertainty and geopolitical risks (GPR). Soybean markets weakly hedge cryptocurrency policy uncertainty, US economic policy uncertainty, and crude oil volatility. In addition, GSCI commodity and crude oil also offer a weak safe-haven property against cryptocurrency uncer…
Educational value of surgical videos on YouTube: quality assessment of laparoscopic appendectomy videos by senior surgeons vs. novice trainees
2019
Background To prepare for surgery, surgeons often recur to surgical videos, with YouTube being reported as the preferred source. This study aimed to compare the evaluation of three surgical trainees and three senior surgeons of the 25 most viewed laparoscopic appendectomy videos listed on YouTube. Additionally, we assessed the video conformity to the published guidelines on how to report laparoscopic surgery videos (LAP-VEGaS). Methods Based on the number of visualization, the 25 most viewed videos on laparoscopic appendectomy uploaded on YouTube between 2010 and 2018 were selected. Videos were evaluated on the surgical technical performance (GOALS score), critical view of safety (CVS), and…
Prediction of type 2 diabetes mellitus based on nutrition data
2021
Abstract Numerous predictive models for the risk of type 2 diabetes mellitus (T2DM) exist, but a minority of them has implemented nutrition data so far, even though the significant effect of nutrition on the pathogenesis, prevention and management of T2DM has been established. Thus, in the present study, we aimed to build a predictive model for the risk of T2DM that incorporates nutrition data and calculates its predictive performance. We analysed cross-sectional data from 1591 individuals from the population-based Cooperative Health Research in the Region of Augsburg (KORA) FF4 study (2013–14) and used a bootstrap enhanced elastic net penalised multivariate regression method in order to bu…
Autoencoders and Recurrent Neural Networks Based Algorithm for Prognosis of Bearing Life
2018
Bearings are one of the most critical components in electric motors, gearboxes and wind turbines. Therefore, bearing fault detection and prognosis of remaining useful life are important to prevent productivity losses. In this study, a novel method is proposed for prognosis of bearing life using an autoencoder and recurrent neural networks-based prediction algorithm. Promising results have been obtained from the experimental data. A monotonic upward trend of the produced health indicator is obtained for all test cases, being one of critical indicators of a proper prognosis. The remaining useful life estimation is moderately accurate under a limited data.
Remote diagnosis and control of wheelchair electrical drive systems
2005
A new Diagnostic and Protective System (DPS) suitable for wheelchair electrical drive applications has been prepared. Such a system is able to perform both monitoring and long-distance transmission of key signals that are used as pre-fault and fault indicators. The system, moreover, may detect several anomalous working conditions by means of reliable diagnosis procedures and carries out actions to protect the electrical drive and to drive the disabled people in safe conditions. In particular the design, the realization and the performance analysis of the new dedicated diagnostic system, which exploits a programmable logic controller (PLC) as DRS hardware, are described and discussed. The ef…
Vacuum induced berry phase: Theory and experimental proposal
2003
We investigate quantum effects in geometric phases arising when a two-level system is interacting with a quantized electromagnetic field. When the system is adiabatically driven along a closed loop in the parameter space, signatures of the field quantization are observable in the geometric phase. We propose a feasible experiment to measure these effects in cavity QED and also analyse the semi-classical limit, recovering the usual Berry phase results.
ACCOUNTING AS A 21ST CENTURY BUSINESS VALUE DRIVER
2017
Companies have focused for decades on maximizing the value creation process of direct productive business activities. The information revolution has left its mark and has started an irreversible transformation of classical business processes and activities. In the new 21st century information and data driven society, commodity is value and knowledge, making Porters value chain concept an important key factor for successful and innovative businesses. Business value creation was during the industrial revolution a topic strictly liked to direct productive activities. The increased and transformed business environment required innovative and sustainable competitive advantages for business organ…
The composite operator method route to the 2D Hubbard model and the cuprates
2018
In this review paper, we illustrate a possible route to obtain a reliable solution of the 2D Hubbard model and an explanation for some of the unconventional behaviours of underdoped high-$T_\text{c}$ cuprate superconductors within the framework of the composite operator method. The latter is described exhaustively in its fundamental philosophy, various ingredients and robust machinery to clarify the reasons behind its successful applications to many diverse strongly correlated systems, controversial phenomenologies and puzzling materials.