scholarly journals Measuring the impact of COVID-19 restrictions on mobility: A real case study from Italy

2021 ◽  
Vol 23 (5) ◽  
pp. 340-349
Author(s):  
Claudia Cavallaro ◽  
Armir Bujari ◽  
Luca Foschini ◽  
Giuseppe Di Modica ◽  
Paolo Bellavista
Keyword(s):  
2021 ◽  
Author(s):  
Joanna Doummar ◽  
Nidal Farran ◽  
Marwan Fahs ◽  
Benjamin Belfort ◽  
Thomas Graf

<p>Climate change and pollution are posing additional unprecedented threats to existing water resources, especially to water supply from karst aquifers in Mediterranean and semi-arid regions. A numerical model considering the most important key hydraulic parameters can forecast the impact of any given input on model quality and quantity output. In this work, we propose to model flow and transport using Comsol multiphysics in a synthetic model and to apply it to a simplified real case study (Jeita spring in Lebanon supplying water to 1.5 million inhabitants). The model geometry consists of a 5300 m long variably saturated horizontal conduit portrayed as 1) 2-D continuum and/or 2) a channel draining a porous equivalent matrix (400 m thick). Flow is simulated using the Richards Equation in both saturated and unsaturated medium. Recharge is applied vertically as both diffuse and point source in a shaft linked to the conduit. Percentages of fast infiltration rates are obtained from the analysis of event time series recorded at the spring (electrical conductivity and discharge). Flow rates at the outlet are used for transient model calibration. Mean velocities, dispersivities, and phreatic conduit diameters obtained from tracer experiments under various flow periods are used for transport validation in the channel. The aim is to test the validity of a functional simplified flow model on a complex real case and to identify based on a sensitivity analysis the key parameters that allow an optimal calibration of such a model. </p>


2020 ◽  
Vol 12 (11) ◽  
pp. 4655 ◽  
Author(s):  
Elena Calvo Gallardo ◽  
Juan Carlos Fernandez de Arroyabe ◽  
Nieves Arranz

This study aims at developing and demonstrating in a real case study a methodology for supporting Occupational Health and Safety Services in the design and assessment of preventive measures to reduce the risks of COVID-19 outbreaks within their entities. The proposed methodology applies the concepts from Social Network Analysis (SNA) to the current challenge of preventing risks of contagion of viruses like SARS-COV-2 among employees. For this purpose, the authors consider a network of employees whose interaction is caused by triggers, which are defined as common circumstances between two workers that may result in contagion, like sharing an office or participating in the same management board. The network cohesion is then evaluated, and those core nodes, which are the most significant contributors to its integration, are identified to be addressed in the design of the preventive measures. The impact of the designed preventive measures on the networks’ cohesion is assessed for its prioritization and further deployment. The methodology has been demonstrated in a real case, a Spanish Research Center, providing promising results in a quick and easy manner. The objective insights provided by its application were demonstrated as very valuable for the Occupational Health and Safety Services in the design and evaluation of the set of preventing measures to be implemented before the return of the employees to the facilities after the Spanish confinement period. The current COVID-19 outbreak brings the need to develop tools and methods to support businesses and institutions in the use of SNA for preventing outbreaks among their employees. Although some literature does exist in the field of SNA application in epidemiology, its adaptation for extensive use by the Occupational and Health Services is still a challenge.


2019 ◽  
Vol 26 (1) ◽  
pp. 9-19
Author(s):  
Ming Kun Li ◽  
Jia Wei Zhang

In many Asian cities, periodic changes in the demand for emergency medical services are concerned, but few existing studies have discussed the time-dependent factor in delivering these services. This study proposes a formula for locating emergency medical services, in which factors of varying demand, time-dependence, cost and facility capacity are considered. A real case is investigated in order to understand the impact of time-dependence on decision making. The case study suggests different solutions depending on whether the design is service-oriented or cost-oriented. The analysis also indicates that the limitations on demand complicate the making of decisions to optimise service locations, e.g., more service stations are required. By creating a design for allocating service sites based on demand nodes in a real case, this study provides a framework for analysing the location problem when demand changes.


2018 ◽  
Author(s):  
Ylber Limani ◽  
Edmond Hajrizi ◽  
Rina Sadriu

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