scholarly journals A robust phenomenological approach to investigate COVID-19 data for France

2021 ◽  
pp. 1-12
Author(s):  
Quentin Griette ◽  
Jacques Demongeot ◽  
Pierre Magal
Keyword(s):  
Mathematical Model ◽  
Phenomenological Model ◽  
Phenomenological Approach ◽  
Daily Basis ◽  
New Method ◽  
Step Process ◽  
Basic Reproductive Ratio ◽  
Time Period ◽  
New Information

We provide a new method to analyze the COVID-19 cumulative reported cases data based on a two-step process: first we regularize the data by using a phenomenological model which takes into account the endemic or epidemic nature of the time period, then we use a mathematical model which reproduces the epidemic exactly. This allows us to derive new information on the epidemic parameters and to compute the effective basic reproductive ratio on a daily basis. Our method has the advantage of identifying robust trends in the number of new infectious cases and produces an extremely smooth reconstruction of the epidemic. The number of parameters required by the method is parsimonious: for the French epidemic between February 2020 and January 2021 we use only 11 parameters in total.

scholarly journals A robust phenomenological approach to investigate COVID-19 data for France

2021 ◽  
Author(s):  
Q. Griette ◽  
J. Demongeot ◽  
P. Magal
Keyword(s):  
Mathematical Model ◽  
Phenomenological Model ◽  
Phenomenological Approach ◽  
Daily Basis ◽  
New Method ◽  
Step Process ◽  
Basic Reproductive Ratio ◽  
Time Period ◽  
New Information

AbstractWe provide a new method to analyze the COVID-19 cumulative reported cases data based on a two-step process: first we regularize the data by using a phenomenological model which takes into account the endemic or epidemic nature of the time period, then we use a mathematical model which reproduces the epidemic exactly. This allows us to derive new information on the epidemic parameters and to compute the effective basic reproductive ratio on a daily basis. Our method has the advantage of identifying robust trends in the number of new infectious cases and produces an extremely smooth reconstruction of the epidemic. The number of parameters required by the method is parsimonious: for the French epidemic between February 2020 and January 2021 we use only 11 parameters in total.

scholarly journals Analysis of the early mother-child relationship in schizophrenic patients

2021 ◽  
pp. 002076402199118
Author(s):  
Marziyeh Khoshgoftar ◽  
Anahita Khodabakhshi-Koolaee ◽  
Mohammad Reza Sheikhi
Keyword(s):  
Cultural Context ◽  
Phenomenological Approach ◽  
Sampling Procedure ◽  
Structured Interviews ◽  
Step Method ◽  
Child Relationship ◽  
New Information ◽  
Data Saturation ◽  
Schizophrenic Patients ◽  
Mother Child Relationship

Background and Aim: The mother as the first caregiver plays a significant role in the formation of the child’s behavior, growth, and communication. The present study aimed to analyze the early mother-child relationship in schizophrenic patients. Materials and Methods: This qualitative study employed a descriptive phenomenological approach. The participants were male patients with schizophrenia who were hospitalized in Qazvin Bahman Psychiatric Hospital from March to September 2020 with an age range of over 18 years. Given the objective of the study, the data were collected using semi-structured interviews. The participants were selected using purposive sampling and the sampling procedure continued until data saturation as the point when no new information is observed in the data. Accordingly, the data were saturated after interviewing 15 participants. The data were analyzed using Colaizzi’s seven-step method. Results: The analysis of the data revealed four main themes including ambivalent attachment to the mother, feelings of constant fear and worry, a sense of constant care for the mother, and a cold and emotionless relationship with the child. Conclusion: The present study suggested that schizophrenia is a disorder that affects the mother-child relationship, and does the term “schizophrenic mothers” need to be reconsidered? However, the result of this research has been done according to the nature and cultural context of Iranian society.

Influence of Tooth Errors and Truing Principles of Grinding Wheel Abrasion for Machining Arc Enveloping Worm

2013 ◽  
Vol 652-654 ◽  
pp. 2153-2158
Author(s):  
Wu Ji Jiang ◽  
Jing Wei
Keyword(s):  
Mathematical Model ◽  
Case Studies ◽  
High Precision ◽  
High Performance ◽  
New Method ◽  
Grinding Wheel ◽  
Grinding Process ◽  
The Mathematical Model

Controlling the tooth errors induced by the variation of diameter of grinding wheel is the key problem in the process of ZC1 worm grinding. In this paper, the influence of tooth errors by d1, m and z1 as the grinding wheel diameter changes are analyzed based on the mathematical model of the grinding process. A new mathematical model and truing principle for the grinding wheel of ZC1 worm is presented. The shape grinding wheel truing of ZC1 worm is carried out according to the model. The validity and feasibility of the mathematical model is proved by case studies. The mathematical model presented in this paper provides a new method for reducing the tooth errors of ZC1 worm and it can meet the high-performance and high-precision requirements of ZC1 worm grinding.

scholarly journals Occlusion of left atrial appendage in patients with atrial fibrillation

2015 ◽  
Vol 18 (4) ◽  
pp. 104 ◽  
Author(s):  
O. N. Ganeeva
Keyword(s):  
Atrial Fibrillation ◽  
Clinical Trials ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Atrial Appendage ◽  
New Method ◽  
Step Process

The article reviews a new method of prophylaxis of thromboembolitic complications, specifically occlusion of left atrial appendage, in patients with atrial fibrillation. Indications and contraindications for the procedure, as well as a step-by-step process of the intervention itself are described. Special emphasis is placed on the up-to-date evidence and the review of clinical trials.

Center-Focus Problem for Discontinuous Planar Differential Equations

2003 ◽  
Vol 13 (07) ◽  
pp. 1755-1765 ◽  
Author(s):  
Armengol Gasull ◽  
Joan Torregrosa
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Critical Point ◽  
Limit Cycles ◽  
New Method ◽  
Polar Coordinates ◽  
Mechanical Problem ◽  
Weak Focus ◽  
Elastic Walls

We study the center-focus problem as well as the number of limit cycles which bifurcate from a weak focus for several families of planar discontinuous ordinary differential equations. Our computations of the return map near the critical point are performed with a new method based on a suitable decomposition of certain one-forms associated with the expression of the system in polar coordinates. This decomposition simplifies all the expressions involved in the procedure. Finally, we apply our results to study a mathematical model of a mechanical problem, the movement of a ball between two elastic walls.

Introduction

2018 ◽  
Author(s):  
M. Kathryn Brown ◽  
George J. Bey
Keyword(s):  
Social Complexity ◽  
Past Research ◽  
Classic Maya ◽  
Maya Lowlands ◽  
Time Period ◽  
New Information ◽  
Preclassic Maya ◽  
Middle Preclassic ◽  
First Time

This introduction to the edited volume by Brown and Bey summarizes past research on the Preclassic Maya and discusses an explosion of new information from the last fifteen years pushing back the origins of social complexity into the Middle Preclassic. This chapter highlights the fact that this volume brings together important archaeology and research considering the Middle and Late Preclassic periods from both the southern and northern Maya lowlands for the first time. The Late Preclassic was long thought to be the time period by which archaeologists could explain the rise and nature of Classic Maya culture. However, as the fifteen chapters in this volume argue, any discussion of the development of social complexity must be focused on the Middle Preclassic (1000-300 B.C.).

Analysis of a breast cancer mathematical model by a new method to find an optimal protocol for HER2-positive cancer

Biosystems ◽  
2020 ◽  
Vol 197 ◽  
pp. 104191
Author(s):  
OPhir Nave ◽  
Miriam Elbaz ◽  
Svetlana Bunimovich-Mendrazitsky
Keyword(s):  
Breast Cancer ◽  
Mathematical Model ◽  
New Method ◽  
Her2 Positive ◽  
Optimal Protocol

A Case Study of Federal Leadership Perspectives on Special Education

2020 ◽  
pp. 002246692090990
Author(s):  
Jeannie Kleinhammer-Tramill ◽  
Zorka Karanxha ◽  
A. Joy Broughton
Keyword(s):  
Special Education ◽  
Special Needs ◽  
Students With Disabilities ◽  
Family Background ◽  
Phenomenological Approach ◽  
Rehabilitation Services ◽  
Education Programs ◽  
Time Period ◽  
The U.S

This article is part of an illustrative study of federal leadership in special education based on interviews with persons who served as Assistant Secretaries in the U.S. Department of Education’s Office of Special Education and Rehabilitation Services and Directors of the Office of Special Education Programs. The perspectives cover the time period since the inception of the HEW—Bureau of Education for the Handicapped in 1967 until 2012. A phenomenological approach to interpreting the data revealed that these leaders faced similar barriers in their efforts to implement their vision, that their family background experiences influenced the policies they pursued, that their accomplishments frame major evolutions of the field, and, that their work represents a lifelong commitment to improving education and services for students with disabilities and special needs. We believe what we learned has value not only in helping to understand the challenges and accomplishments that have passed but also in its potential for guiding the future of federal and other legislation protecting the rights of and improving and sustaining the services needed for individuals with disabilities.

Mathematical Model and Algorithm of Soy Sauce Quality Evaluation Based on Fuzzy Clustering

2011 ◽  
Vol 55-57 ◽  
pp. 2018-2022
Author(s):  
Yu Feng Li ◽  
Chun Ling Wang
Keyword(s):  
Mathematical Model ◽  
Fuzzy Clustering ◽  
Quality Evaluation ◽  
Soy Sauce ◽  
New Method ◽  
The Mathematical Model

A mathematical model is created, and the algorithm is designed according to the fuzzy clustering. The main indices of the soy sauce samples are detected, and the data are analyzed using fuzzy clustering. As a result, many classes including different soy sauce sample can be obtained, and the quality within the same class is similar. The mathematical model and algorithm provide a method to identification the soy sauce. And in the others, it provides a new method to evaluate the quality of the soy sauce.

A Mathematics Model for Quantitative Analysis of Demand Disruption Caused by Rumor Spreading

2014 ◽  
Vol 13 (03) ◽  
pp. 585-602 ◽  
Author(s):  
Haifeng Zhao ◽  
Bin Lin ◽  
Chongqing Guo
Keyword(s):  
Mathematical Model ◽  
Supply Chain ◽  
Quantitative Analysis ◽  
New Method ◽  
Mathematics Model ◽  
Rumor Spreading ◽  
On Demand ◽  
Spreading Model ◽  
Internet Age ◽  
Purchasing Intention

Rumors greatly impact consumers' attitudes and purchasing intention. Rumor spreading can disrupt supply chain demand, particularly in today's Internet age. We propose a mathematical model for the quantitative analysis of demand disruption caused by rumor spreading based on the susceptible-infective-isolated-immune (SI2I) rumor spreading model, which extends the susceptible-infective-recovered (SIR) rumor spreading model by dividing stiflers into isolators and immunes. Both groups represent individuals who do not propagate a rumor, but the former believes the rumor while the latter does not. From the firms' perspective, only ignorants and immunes will still purchase their products and services after a rumor has spread. Hence, the influence of rumors on demand can be quantitatively reflected by the proportion of ignorants and immunes in the population. This study offers a new method for company managers to predict the variation trend of demand and estimate demand loss when a firm is attacked by rumors.

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