scholarly journals A Control Based Mathematical Model for the Evaluation of Intervention Lines in COVID-19 Epidemic Spread: The Italian Case Study

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 890
Author(s):  
Paolo Di Giamberardino ◽  
Rita Caldarella ◽  
Daniela Iacoviello

This paper addresses the problem of describing the spread of COVID-19 by a mathematical model introducing all the possible control actions as prevention (informative campaign, use of masks, social distancing, vaccination) and medication. The model adopted is similar to SEIQR, with the infected patients split into groups of asymptomatic subjects and isolated ones. This distinction is particularly important in the current pandemic, due to the fundamental the role of asymptomatic subjects in the virus diffusion. The influence of the control actions is considered in analysing the model, from the calculus of the equilibrium points to the determination of the reproduction number. This choice is motivated by the fact that the available organised data have been collected since from the end of February 2020, and almost simultaneously containment measures, increasing in typology and effectiveness, have been applied. The characteristics of COVID-19, not fully understood yet, suggest an asymmetric diffusion among countries and among categories of subjects. Referring to the Italian situation, the containment measures, as applied by the population, have been identified, showing their relation with the government's decisions; this allows the study of possible scenarios, comparing the impact of different possible choices.

Transport ◽  
2006 ◽  
Vol 21 (4) ◽  
pp. 278-283 ◽  
Author(s):  
Sunday Ayoola Oke ◽  
Ayokunle Bamigbaiye ◽  
Oluwafemi Isaac Oyedokun ◽  
Oliver Ekpere Charles-Owaba

The purpose of this paper is to develop a mathematical model that could guide certain speed limits for vehicles on roads. Excessive speeds on roads have been a major indirect cause of deaths on highways due to the sudden impact of vehicles that lead to accidents. The model presented here is developed on a measure of impact force of two vehicles engaged in a head‐on collision. A hypothetical case study was investigated based on the impact of force on the human body. The results showed a variation of speed with occupation position distance. The paper also examines the role of seatbelt as a safety feature for vehicle occupants. Practically, developing a quantitative approach for evaluating the impacts of speed would help road regulatory authorities in reducing accidents and deaths on roads. It would also assist them in tracking “road traffic offenders” by setting controls to which road users must conform.


2020 ◽  
pp. 108-115 ◽  
Author(s):  
Vladimir P. Budak ◽  
Anton V. Grimaylo

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.


2020 ◽  
Vol 15 (2) ◽  
pp. 95-109
Author(s):  
Heba Aziz ◽  
Osman El-Said ◽  
Marike Bontenbal

The objective of this study was to measure the level of cruise tourists' satisfaction as well as the relationship between satisfaction, recommendation, return intention, and expenditure. Also, the impact of factors such as nationality, length of the visit, and age on the level of expenditure was measured. An empirical approach for data collection was followed and a total of 152 questionnaires were collected from cruise tourists visiting the capital city of Oman, Muscat, as cruise liners anchor at Sultan Qaboos Port. Results of the regression analysis supported the existence of a causal relationship between satisfaction with destination attributes, overall satisfaction, recommendation, return intention, and expenditure. It was found that the average expenditure varies according to age and length of the visit. Recommendations for policy makers were suggested on how to increase the role of cruise tourism in strengthening the economy.


Author(s):  
Maria Ricciardi ◽  
Concetta Pironti ◽  
Oriana Motta ◽  
Rosa Fiorillo ◽  
Federica Camin ◽  
...  

AbstractIn this paper, we analysed the efflorescences present in the frescos of a monumental complex named S. Pietro a Corte situated in the historic centre of Salerno (Campania, Italy). The groundwater of the historic centre is fed by two important streams (the Rafastia and the Fusandola) that can be the sources of water penetration. The aims of this work are to (i) identify the stream that reaches the ancient frigidarium of S. Pietro a Corte and (ii) characterize the efflorescences on damaged frescos in terms of chemical nature and sources. In order to accomplish the first aim, the water of the Rafastia river (7 samples) and the water of the Fusandola river (7 samples) were analysed and compared with the water of a well of the Church (7 samples). The ionic chromatography measurements on the water samples allowed us to identify the Rafastia as the river that feeds the ancient frigidarium of S. Pietro a Corte. To investigate the nature and the origin of the efflorescences (our second aim), anionic chromatography analyses, X-ray diffraction measurements, and the isotopic determination of nitrogen were performed on the efflorescences (9 samples) and the salts recovered from the well (6 samples). Results of these analyses show that efflorescences are mainly made of potassium nitrate with a δ15N value of + 9.3 ± 0.2‰. Consequently, a plausible explanation for their formation could be the permeation of sewage water on the walls of the monumental complex.


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ricardo Jorge Oliveira ◽  
Bruna Santos ◽  
Maria J. Mota ◽  
Susana R. Pereira ◽  
Pedro C. Branco ◽  
...  

Abstract Lignocellulosic biomass represents a suitable feedstock for production of biofuels and bioproducts. Its chemical composition depends on many aspects (e.g. plant source, pre-processing) and it has impact on productivity of industrial bioprocesses. Numerous methodologies can be applied for biomass characterisation, with acid hydrolysis being a particularly relevant step. This study intended to assess the most suitable procedures for acid hydrolysis, taking Eucalyptus globulus bark as a case study. For that purpose, variation of temperature (90–120 °C) was evaluated over time (0–5 h), through monosaccharides and oligosaccharides contents and degradation. For glucose, the optimal conditions were 100 °C for 2.5 h, reaching a content of 48.6 wt.%. For xylose, the highest content (15.2 wt.%) was achieved at 90 °C for 2 h, or 120 °C for 0.5 h. Maximum concentrations of mannose and galactose (1.0 and 1.7 wt.%, respectively) were achieved at 90 and 100 °C (2–3.5 h) or at 120 °C (0.5–1 h). These results revealed that different hydrolysis conditions should be applied for different sugars. Using this approach, total sugar quantification in eucalyptus bark was increased by 4.3%, which would represent a 5% increase in the ethanol volume produced, considering a hypothetical bioethanol production yield. This reflects the importance of feedstock characterization on determination of economic viability of industrial processes.


Author(s):  
Rade M. Ciric ◽  
Sasa N. Mandic

AbstractThe Republic of Serbia must make significant efforts to promote and exploit renewable energy sources and increase energy efficiency in all energy sectors to ensure energy security and economic competitiveness, reduce the negative impact on the environment from energy production and use, and contribute to global efforts to reduce greenhouse gases. Within the paper several issues of integration of recently realized CHP plant are introduced and discussed. Firstly, the legal and energy policy issues in the Republic of Serbia regarding connecting CHP to the grid are presented. The challenges and technical solutions for CHP connection to the grid, as well as power quality issues and the role of the CHP plant during the restoration of power supply during the maintenance of the substation and unplanned loss of high voltage supply, are presented and discussed. Finally, the impact of prospective massive integration of CHP on the energy balance and CO2 emission reduction in the province of Vojvodina in Serbia is investigated and discussed. Since it is the first CHP plant realized in Serbia, it is crucial that experience be shared to all potential stakeholders in the future energy efficiency projects.


Author(s):  
Oriol Ríos-González ◽  
Mimar Ramis-Salas ◽  
Juan Carlos Peña-Axt ◽  
Sandra Racionero-Plaza

Background: Men who develop behaviors connected with the model of hegemonic masculinity present several health problems. Previous research has shown the types of problems that men commonly suffer in this regard such as chronic diseases, dietary disorders, and traffic accidents. To combat and overcome this situation, several campaigns, policies and recommendations have been undertaken, and consequently, their influence has been analyzed. However, there have been few investigations into the role of men’s friendship in the reduction of these physical health problems. The findings presented in this article are focused on this issue, illustrating the impact of male friendship on the shaping of healthy behaviors. Methods: Drawing upon a qualitative-based methodology articulated in a case study of the Men in Dialogue association, located in Spain, the study has followed the premises of the communicative approach, a total of 15 structured online open-ended questionnaires have been performed and analyzed. The median age of the participants is 37.5 years. Results: The findings show how men involved in Men in Dialogue are promoting a kind of masculine friendship that is improving men’s emotional well-being and, consequently, their physical health.


2015 ◽  
Vol 37 ◽  
pp. 1560053
Author(s):  
Pedro Jimenez-Delgado

Reports on our latest extractions of parton distribution functions of the nucleon are given. First an overview of the recent JR14 upgrade of our unpolarized PDFs, including NNLO determinations of the strong coupling constant and a discussion of the role of the input scale in parton distribution analysis. In the second part of the talk recent results on the determination of spin-dependent PDFs from the JAM collaboration are reported, including a careful treatment of hadronic and nuclear corrections, as well as reports on the impact of present and future data in our understanding of the spin of the nucleon.


2006 ◽  
Vol 24 (5) ◽  
pp. 327-345 ◽  
Author(s):  
Loïc Plé

PurposeThe purpose of this research is to explore the combining of marketing and organizational literature. This paper seeks to evaluate the relationships between multichannel coordination and customer participation, as seen through the lens of potential customer opportunism. It aims at showing the impact of this opportunism on the organizational design of multiple channels structures.Design/methodology/approachThe research reports on an exploratory case study in a French retail bank. A total of 25 in‐depth interviews were conducted, and the use of other sources enabled data triangulation.FindingsThe results show first that an increase in the number of distribution channels is liable to favor customer opportunistic behavior. To counter this, the bank mainly relies on impersonal coordination modes. An emerging result highlights the role of the customer as a “perceptual filter” between the different channels of employees.Research limitations/implicationsCustomer opportunism is studied via channels employees perceptions. An investigation using a customer survey may help to better understand this construct, e.g. to identify its antecedents, and to measure it precisely. Moreover, further qualitative and/or quantitative studies with larger sample sizes are needed to try and generalize these results.Practical implicationsIt is recommended not to forget that customers can facilitate or hinder multichannel coordination. Retail banks have the power to use them conveniently, provided that they are fully conscious of the scope of the “partial employee” role played by the customer.Originality/valueThis paper broadens understanding of how multichannel distribution structures are coordinated, and in a way belies traditional organizational design literature. The emerging result gives birth to the concept of “reversed interactive marketing”, which has interesting theoretical and practical repercussions.


Author(s):  
Rizki Mohamed

The Tagueleft basin is geographically located in the northern edges of the Middle High Atlas, which is a geomorphological fragile area. The impact of human activity has accelerated water erosion in this mountains area. This is reflected in dynamic and unstable foothills, a decrease in forests density and degradation in the production of the land. On the other hand, land degradation due to human overexploitation of natural resources has increased land degradation in the area. The interest in the risk of erosion on the foothills in the area under study comes in the context of our contribution to clarify the role of geomatical and geomorphological approaches in explaining and identifying the mechanisms responsible for current foothills dynamism through water erosion and its negative impacts on the environment and local development. The aim of the study was to use the EPM (Erosion Potential Méthod) which is formulated by Slobodan Gavrilovic for erosion in mountainous areas and to test the reliability of its results based on fieldwork and remote sensing data. The results of the erosion assessment and its quantification by applying the coefficient (W) for the theoretical model in the area under study have shown that erosion is very important and it touches on wide areas as it appears through the domain classification of the distribution erosion in Tagueleft basin.


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