scholarly journals Determination of the Course of COVID-19 Pandemic Using Modified Logistic Modeling

Introduction: COVID-19 appeared in China at the end of 2019. It then spread all over the world very quickly. The new type of corona virus COVID-19, which causes respiratory tract infection, is destructive with its high rate of transmission and mortality rate. Materials and Methods: In this study, determining the course of the COVID-19 pandemic for next 4 months in Afghanistan with the help of a specially modified mathematical modeling is intended to reveal. Results: results of our study show that the COVID-19 pandemic can affect a large population in Afghanistan in a short time. However, it is possible to reduce the number of cases and deaths very effectively with easy measures. Keywords: COVID-19, precautions, pandemic, logistic mathematical model, Afghanistan.

2020 ◽  
Vol 5 (1) ◽  
pp. 61-68
Author(s):  
Rustan Rustan ◽  
Linda Handayani

Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by a new type of virus called SARS-CoV-2, and by the beginning of 2020 had spread throughout the world, including Indonesia. A high rate of spread of COVID-19 causes the number of patients that infected increase significantly. In this study, mathematical modeling was carried out to predict the number of COVID-19 patients and the duration of the COVID-19 pandemic in Indonesia. The model used is a modified SEIR model (Susceptible, Exposed, Infected, Recovered) with several assumptions such as a constant and homogeneous population, patients who have recovered can not be infected, and the spread only occurs from human to human. In addition,  it is assumed that there are individuals who carry out quarantine and isolation. Modeling is done using the help of MATLAB R2015a. The modeling results show that the peak of the COVID-19 pandemic in Indonesia will occur in the middle of May 2020, and the number of infected patients will be about 15000 people. This amount can be reduced if the quarantine and self-isolation process is carried out optimally.


Author(s):  
D.V. Lipatov ◽  
◽  
S.A. Skladchikov ◽  
N.P. Savenkova ◽  
V.V. Novoderezkin ◽  
...  

Background. The avalanche-like growth of intravitreal injections in the world has significantly increased interest in the hemodynamics of the processes that occur in the eye when a drug is injected into the vitreous cavity. Every year, the number of intravitreally used drugs and promising areas in which they can be used is growing. This also applies to the creation of new combined medicines and the development of drugs with a long-term therapeutic effect. Aims. Create mathematical model of eyeball to evaluate the movement of the drug substance in it; to estimate the time of the drug's presence in the eye cavity before its complete removal, to characterize the ways of its removal from the eye cavity; to assess the significance of posterior vitreous detachment during the time when the drug is present in the eye cavity; to evaluate the effect on the hydrodynamics of the depth of drug administration. Results. When the drug is administered closer to the center of the eyeball, its residence time increases in comparison with the parietal administration. With a complete posterior detachment of the vitreous body, the time of finding the drug in the eye is prolonged compared to its absence. The obtained results of mathematical modeling of the movement of the drug administered intravitreally cannot be mechanically transferred to the human eye, due to the more complex structure of the latter. Key words: intravitreal injections, vitreous body, mathematic computing.


Author(s):  
Edmunds Teirumnieks ◽  
Ērika Teirumnieka ◽  
Ilmārs Kangro ◽  
Harijs Kalis

Metals deposition in peat can aid to evaluate impact of atmospheric or wastewaters pollution and thus can be a good indicator of recent and historical changes in the pollution loading. For peat using in agriculture, industrial, heat production etc. knowledge of peat metals content is important. Experimental determination of metals in peat is very long and expensive work. Using experimental data the mathematical model for calculation of concentrations of metals in different points for different layers is developed. The values of the metals (Ca, Mg, Fe, Sr, Cu, Zn, Mn, Pb, Cr, Ni, Se, Co, Cd, V, Mo) concentrations in different layers in peat taken from Knavu peat bog from four sites are determined using inductively coupled plasma optical emission spectrometer. Mathematical model for calculation of concentrations of metal has been described in the paper. As an example, mathematical models for calculation of Pb concentrations have been analyzed.


Author(s):  
V. Yu. Beglyakov ◽  
V. V. Aksenov ◽  
I. K. Kostinets ◽  
A. A. Khoreshok

The processes occurring during the geodetic excavation of underground excavations are characterized by the interaction of the elements of the geokhod with each other and with the geo-environment. The interaction process can be investigated in mathematical modeling, solving the problems of justifying the parameters of the drives and interacting forces, ensuring sufficient strength of the machine elements and the bearing capacity of the contour array. The proposed block-modular principles of constructing a mathematical model allow solving particular problems of the system and its individual elements. From the solution of particular problems, it is now necessary to proceed to the solution of the generalized model, using equivalent loads and reduced total moments (forces). The construction of a generalized model requires a number of assumptions, but its solution will reveal the interaction between the elements of the geokhod and the geo-environment, which is very relevant.As an example, the solution of a particular problem is given-the determination of the value of the forces arising from the interaction of the blade of an external engine with the medium.A list of assumptions is formulated that allow us to describe a general mathematical model of the interaction between the geo-environment and the geokhod, as well as the processes occurring during geodetic excavation of mine workings.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pablo Refoyo Román ◽  
Cristina Olmedo Salinas ◽  
Benito Muñoz Araújo

Abstract Energy production by wind turbines has many advantages. The wind is a renewable energy that does not emit greenhouse gases and has caused a considerable increase in wind farms around the world. However, this type of energy is not completely free of impact. In particular, wind turbines displace and kill a wide variety of wild species what forces us to plan their location well. In any case, the determination of the effects of wind farms on fauna, especially the flying one, is difficult to determine and depends on several factors. In this work, we will try to establish a mathematical algorithm that allows us to combine all variables that affect the species with the idea of quantifying the effect that can cause the installation of a wind farm with certain characteristics in a given place. We have considered specific parameters of wind farms, the most relevant environmental characteristics related to the location of the wind farm, and morphological, ethological and legal characteristics in the species. Two types of assessment are established for the definitive valuation. Total Assessment and Weighted Assessment. Total Valuation is established based on a reference scale that will allow us to establish categories of affection for the different species while Weighted valuation allows us to establish which species are most affected.


2021 ◽  
Vol 7 (1) ◽  
pp. 29-35
Author(s):  
German V. Nedugov

Background: The constancy of the ambient temperature is the main condition to correctly determine the time of death by thermometric method. However, in practice, this requirement is met only in cases of death in closed rooms. In this study, an exponential mathematical model was proposed for corpse cooling under any changes in ambient temperature. Aim: This study aimed to develop a mathematical model to determine the time of death based on the NewtonRichman cooling law in changing ambient temperature conditions. Materials and methods: Mathematical modeling of corpse cooling under changing ambient temperature is performed, focusing on problem solving of thermometric determination of the time of death. The axillary hollow was used as the diagnostic zone of the corpse, and the temperature of which at the time of death is taken is 36.6С. Results: A method of reverse reproduction of the cadaver temperature in conditions of changing ambient temperature has been developed. Results allow a relatively simple analytical determination of the time of death in the early postmortem period. Conclusions: The proposed method is advisable to be used in forensic medical practice to determine the time of death in early postmortem period. The developed mathematical model is implemented in the format of the application program Warm Bodies NRN. Use of tympanic and intraocular thermometry was recommended within the proposed model.


2021 ◽  
Vol 22 (4) ◽  
pp. 595-608
Author(s):  
A. Molter ◽  
R. S. Quadros ◽  
M. Rafikov ◽  
D. Buske ◽  
G. A. Gonçalves

The outbreak of COVID-19 has made scientists from all over the world do not measureefforts to understand the dynamics of the disease caused by this coronavirus. Several mathematical models have been proposed to describe the dynamics and make predictions. This work proposes a mathematical model that includes social isolation of susceptible individuals as a strategy of suppression and mitigation of the disease. The Susceptible-Infectious-Isolated-Recovered-Dead (SIQRD) model is proposed to analyze three important issues about the dynamics of the disease taking into account social isolation: when the isolation should begin? How long to keep the isolation? How to get out of this isolation? To get answers, computer simulations are provided and their results discussed. The results obtained show that beginning social isolation on the 10th or 15th days, after confirmation of the 50th case, and with 70% of the population in isolation, seems to be promising, since the infected curve does not grow much until it enters the isolation and remains at a stable level during the isolation. On the other hand an abrupt release of the social isolation will imply a second peak of infected individuals above the first one, which is not desired. Therefore, the release from social isolation should be gradual.


2017 ◽  
Vol 6 (4) ◽  
pp. 60
Author(s):  
Hans Albert Braunfisch

<p>Daesh, or Islamic State, holds captive the fears of populations the world over. However, with the advent of this new type of terror organization functioning as a pseudo-state, the approach to eliminating it must also be adapted, but in order to eliminate such a threat, it must first be understood. As of now, the understanding of Daesh widely varies depending upon the source. They are likened to other terror organizations, insurrections, unrecognized states, and caliphates of antiquity. To make the concept and understanding of Daesh more comprehensible to members of the private sector, the author utilizes a framework common for consultancies and management teams, the S.W.O.T. Analysis, to depict the organization’s assets, shortcomings, potentials for growth, and hazards. Following this analysis, the author paints Daesh as a product of its environment. With instability in the Middle East, a large population of disgruntled, young men, and globalization via social media, Daesh has become not only a pseudo-state to destroy, but an ideology that permeates inexistent cyber borders. As a result, implications for policy revision and reflection are vital for preventative measures. The author suggests leaders’ future approaches involve less armed intervention to preserve governments and greater investment in aid. These two methods create a stable environment in which the populace can focus on economic and personal development, as opposed to ideological conflict.</p>


2013 ◽  
Vol 2 (1) ◽  
pp. 104-109
Author(s):  
Arti R Golhar ◽  
P.S. Sawadh ◽  
N. K. Choudhari

Predicting the type of aluminium metals and composition of elements present in the aluminium samples through Nondestructive testing (NDT) is a matter of very importance for aluminium Industry. The unique method to determine grade of the aluminium sample is required to characterize the aluminium metals. The Nondestructive Technique (NDT) and determination of characteristics and mechanical properties of aluminium metals are used to identify the grade of aluminium metals so that accordingly it can be used for the specific applications. Therefore a technique is required to predict the percentage of aluminium, Iron, Copper, Manganese of aluminium metals so as to categorize into different grades and applications. In Aluminium samples percentage of Aluminium plays very important role which may help to decide the grade of the aluminium metals hence its applications. The present work is focused on how the percentage of aluminium in aluminium samples can be calculated by adopting the mathematical modeling technique.     There are various parameters which generally affect the percentage of aluminium in aluminium samples, and play a very major role. Therefore through this investigation an attempt is being made to formulate an approximate mathematical model which will certainly predict the percentage of aluminium in aluminium samples. In advent of this a dimensionless pie terms of various prominent parameters or variables have been taken to form a mathematical model. Some of these variables used to formulate this model are given as follows (i) physical properties of the aluminium samples like hardness, density, modulus of elasticity etc (ii) Signal analysis properties like Peak amplitude of Time signal, FFT, PSD and (iii) both the properties. The data of such types of variables have been recorded and calculated and thus the formulation of model is being done by multiple regression analysis. The model is then optimized and the reliability of the model has also been estimated. In fact this type of model will be helpful to estimate the aluminium percentage.


Author(s):  
Ērika Teirumnieka ◽  
Ilmārs Kangro ◽  
Edmunds Teirumnieks ◽  
Harijs Kalis ◽  
Aigars Gedroics

Bogs have been formed by an accumulation of peat - a light brown-to-black organic material, built up from partial decomposition of mosses and other bryophytes, sedges, grasses, shrubs, or trees under waterlogged conditions. The total peatlands area in Latvia covers 698 918 ha or 10.7% of the entire territory. Knowledge’s of peat metals content are important for any kind of peat using. Experimental determination of metals in peat is very long and expensive work. Using experimental data mathematical model for calculation of concentrations of metals in different points for different layers can help to very easy and fast to find approximately concentration of metals or trace elements. The results of the research show that concentrations of trace elements in peat are generally low. Concentrations differ between the superficial, middle and bottom peat layers, but the significance decreases depending on the type of mire. The mathematical model for calculation of concentration of metals in different points for different 3 layers in peat blocks is developed. As an example, mathematical models for calculation of Ca and Fe concentrations have been analyzed.


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