Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
1.
Sci Rep ; 13(1): 3405, 2023 Feb 28.
Article in English | MEDLINE | ID: mdl-36854757

ABSTRACT

In this paper, the feasibility of Structural Health Monitoring (SHM) employing a novel Fibonacy Sequence (FS)-based Optimization Algorithms (OAs) and up-to-date computing techniques is investigated for a large-scale railway bridge. During recent decades, numerous metaheuristic intelligent OAs have been proposed and immediately gained a lot of momentum. However, the major concern is how to employ OAs to deal with real-world problems, especially the SHM of large-scale structures. In addition to the requirement of high accuracy, a high computational cost is putting up a major barrier to the real application of OAs. Therefore, this article aims at addressing these two aforementioned issues. First, we propose employing the optimal ability of the golden ratio formulated by the well-known FS to remedy the shortcomings and improve the accuracy of OAs, specifically, a recently proposed new algorithm, namely Salp Swarm Algorithm (SSA). On the other hand, to deal with the high computational cost problems of OAs, we propose employing an up-to-date computing technique, termed superscalar processor to conduct a series of iterations in parallel. Moreover, in this work, the vectorization technique is also applied to reduce the size of the data. The obtained results show that the proposed approach is highly potential to apply for SHM of real large-scale structures.

2.
Sci Rep ; 12(1): 4958, 2022 03 23.
Article in English | MEDLINE | ID: mdl-35322158

ABSTRACT

Artificial neural network (ANN) has been commonly used to deal with many problems. However, since this algorithm applies backpropagation algorithms based on gradient descent (GD) technique to look for the best solution, the network may face major risks of being entrapped in local minima. To overcome those drawbacks of ANN, in this work, we propose a novel ANN working parallel with metaheuristic algorithms (MAs) to train the network. The core idea is that first, (1) GD is applied to increase the convergence speed. (2) If the network is stuck in local minima, the capacity of the global search technique of MAs is employed. (3) After escaping from local minima, the GD technique is applied again. This process is applied until the target is achieved. Additionally, to increase the efficiency of the global search capacity, a hybrid of particle swarm optimization and genetic algorithm (PSOGA) is employed. The effectiveness of ANNPSOGA is assessed using both numerical models and measurement. The results demonstrate that ANNPSOGA provides higher accuracy than traditional ANN, PSO, and other hybrid ANNs (even a higher level of noise is employed) and also considerably decreases calculational cost compared with PSO.


Subject(s)
Algorithms , Neural Networks, Computer
3.
Sci Rep ; 11(1): 6481, 2021 03 19.
Article in English | MEDLINE | ID: mdl-33742072

ABSTRACT

The novel Coronavirus-2019 (COVID-19) was declared a pandemic by the World Health Organization (WHO) in March 2020, impacting the lifestyles, economy, physical and mental health of individuals globally. This study aimed to test the model triggered by physical symptoms resembling COVID-19 infection, in which the need for health information and perceived impact of the pandemic mediated the path sequentially, leading to adverse mental health outcomes. A cross-sectional research design with chain mediation model involving 4612 participants from participating 8 countries selected via a respondent-driven sampling strategy was used. Participants completed online questionnaires on physical symptoms, the need for health information, the Impact of Event Scale-Revised (IES-R) questionnaire and Depression, Anxiety and Stress Scale (DASS-21). The results showed that Poland and the Philippines were the two countries with the highest levels of anxiety, depression and stress; conversely, Vietnam had the lowest mean scores in these areas. Chain mediation model showed the need for health information, and the perceived impact of the pandemic were sequential mediators between physical symptoms resembling COVID-19 infection (predictor) and consequent mental health status (outcome). Excessive and contradictory health information might increase the perceived impact of the pandemic. Rapid COVID-19 testing should be implemented to minimize the psychological burden associated with physical symptoms, whilst public mental health interventions could target adverse mental outcomes associated with the pandemic.


Subject(s)
Anxiety/diagnosis , COVID-19/diagnosis , Depression/diagnosis , Stress, Psychological/diagnosis , Anxiety/psychology , Asia/epidemiology , Cross-Sectional Studies , Depression/psychology , Europe/epidemiology , Humans , Mental Health , Outcome Assessment, Health Care , Stress, Psychological/psychology , Surveys and Questionnaires , United States/epidemiology
4.
PLoS One ; 16(2): e0246824, 2021.
Article in English | MEDLINE | ID: mdl-33571297

ABSTRACT

The coronavirus disease (COVID-19) pandemic has impacted the economy, livelihood, and physical and mental well-being of people worldwide. This study aimed to compare the mental health status during the pandemic in the general population of seven middle income countries (MICs) in Asia (China, Iran, Malaysia, Pakistan, Philippines, Thailand, and Vietnam). All the countries used the Impact of Event Scale-Revised (IES-R) and Depression, Anxiety and Stress Scale (DASS-21) to measure mental health. There were 4479 Asians completed the questionnaire with demographic characteristics, physical symptoms and health service utilization, contact history, knowledge and concern, precautionary measure, and rated their mental health with the IES-R and DASS-21. Descriptive statistics, One-Way analysis of variance (ANOVA), and linear regression were used to identify protective and risk factors associated with mental health parameters. There were significant differences in IES-R and DASS-21 scores between 7 MICs (p<0.05). Thailand had all the highest scores of IES-R, DASS-21 stress, anxiety, and depression scores whereas Vietnam had all the lowest scores. The risk factors for adverse mental health during the COVID-19 pandemic include age <30 years, high education background, single and separated status, discrimination by other countries and contact with people with COVID-19 (p<0.05). The protective factors for mental health include male gender, staying with children or more than 6 people in the same household, employment, confidence in doctors, high perceived likelihood of survival, and spending less time on health information (p<0.05). This comparative study among 7 MICs enhanced the understanding of metal health in the general population during the COVID-19 pandemic.


Subject(s)
Anxiety/etiology , COVID-19/epidemiology , Depression/etiology , Mental Health , Stress, Psychological/etiology , Adolescent , Adult , Anxiety/diagnosis , Anxiety/psychology , Asia/epidemiology , COVID-19/psychology , Child , Cross-Sectional Studies , Depression/diagnosis , Depression/psychology , Female , Humans , Male , Middle Aged , Protective Factors , SARS-CoV-2/isolation & purification , Sex Factors , Socioeconomic Factors , Stress, Psychological/diagnosis , Stress, Psychological/psychology , Young Adult
5.
Trop Med Int Health ; 26(2): 228-236, 2021 02.
Article in English | MEDLINE | ID: mdl-33164300

ABSTRACT

OBJECTIVES: Pregnant women and new mothers are among the most vulnerable to seasonal influenza; however, little is known about their preferences for flu vaccination. We examined the rural-urban differences in uptake, demand and willingness to pay (WTP) for influenza vaccination among women of childbearing age, to assess the feasibility of implementing locally produced vaccines in Vietnam. METHODS: A cross-sectional study was performed in both urban and rural areas of Hanoi in 2018. Socio-demographic characteristics, history of vaccination, demand and WTP for influenza vaccines were obtained. A multivariate logistic regression model was employed to identify the associated factors. RESULTS: Of 750 participants, 29.9% had had flu shots in the current or previous flu season and 64.3% indicated demand for this vaccine. The median of the maximum amount of WTP for influenza vaccination services was US$ 8.5 (IQR: 8.5-17.0). Women living in rural areas had a significantly lower uptake and higher demand, and were willing to pay less than women in urban locations (21.1% vs. 36.6%; 69% vs. 60.2%; and US $8.5 vs. US $11.7, respectively). For urban participants, factors associated with higher demand and WTP for flu shots included having ANC in health facilities and having been vaccinated against influenza in the past; for rural women, these factors were having suffered from influenza and hearing about it. CONCLUSIONS: This study informs the feasibility of implementing locally produced influenza vaccines in Vietnam. Educational programs, along with counselling services and government subsidies, should be implemented to improve the coverage, demand and WTP for the vaccine.


OBJECTIFS: Les femmes enceintes et les nouvelles mères sont parmi les plus vulnérables à la grippe saisonnière; cependant, on en sait peu sur leurs préférences pour la vaccination contre la grippe. Nous avons examiné les différences entre les zones rurales et urbaines dans l'adoption, la demande et la volonté de payer pour la vaccination antigrippale chez les femmes en âge de procréer, afin d'évaluer la faisabilité de la mise en œuvre de vaccins produits localement au Vietnam. MÉTHODES: Une étude transversale a été réalisée dans les zones urbaines et rurales de Hanoi en 2018. Les caractéristiques sociodémographiques, les antécédents de vaccination, la demande et la volonté de payer pour les vaccins antigrippaux ont été obtenus. Un modèle de régression logistique multivariée a été utilisé pour identifier les facteurs associés. RÉSULTATS: Sur 750 participantes, 29,9% s'étaient fait vacciner contre la grippe au cours de la saison grippale actuelle ou précédente, 64,3% ont indiqué une demande pour ce vaccin. La médiane du montant maximal de la volonté de payer pour les services de vaccination contre la grippe était de 8,5 USD (IQR: 8,5 à 17,0). Les femmes vivant dans les zones rurales avaient une adoption nettement plus faible, une demande plus élevée et étaient prêtes à payer moins que les femmes des zones urbaines (21,1% contre 36,6%; 69% contre 60,2%; et 8,5 USD contre 11,7 USD, respectivement). Pour les participantes urbaines, les facteurs associés à une demande plus élevée et à la volonté de payer pour les vaccins contre la grippe comprenaient le fait d'avoir des soins prénatals dans les établissements de santé et d'avoir été vaccinés contre la grippe dans le passé; pour les femmes rurales, ces facteurs comprenaient, avoir souffert de la grippe et en avoir entendu parler. CONCLUSIONS: Cette étude informe sur la faisabilité de la mise en œuvre de vaccins antigrippaux produits localement au Vietnam. Des programmes éducatifs, ainsi que des services de conseil et des subventions gouvernementales devraient être mis en œuvre pour améliorer la couverture, la demande et la volonté de payer pour le vaccin.


Subject(s)
Influenza Vaccines/administration & dosage , Influenza, Human/prevention & control , Patient Acceptance of Health Care/statistics & numerical data , Pregnancy Complications, Infectious/prevention & control , Vaccination/statistics & numerical data , Adult , Cross-Sectional Studies , Female , Humans , Influenza Vaccines/economics , Logistic Models , Multivariate Analysis , Pregnancy , Prenatal Care , Rural Population/statistics & numerical data , Urban Population/statistics & numerical data , Vaccination/economics , Vietnam , Young Adult
6.
J Phys Chem A ; 122(42): 8259-8273, 2018 Oct 25.
Article in English | MEDLINE | ID: mdl-30196692

ABSTRACT

In an attempt to construct detailed kinetic mechanisms for biodiesel fuels on the fly, high-pressure rate rules for the concerted HO2 elimination reaction class were derived using a comprehensive training reaction set of more than 60 reactions involving different alkyl methyl/ethyl ester peroxy radicals (RCOOR')-OO•. Using the composite electronic structure method CBS-QB3 in combination with classical statistical mechanics and the transition state theory (TST) rate model, high-pressure rate constants for the reactions in the training set as well as thermodynamic properties for the species involved were calculated. The corrections from Eckart tunneling and hindered internal rotation (HIR) treatments were also included in the calculations. The results reveal that the ester group (-COO-) selectively promotes the reaction when compared with the traditional hydrocarbon fuels; thus it is recommended that the seven derived rate rules for the title reaction class (including the thermodynamic data of the species involved in the NASA format) should be used for construction of detailed kinetic mechanisms for real biodiesel molecules.

7.
Adv Colloid Interface Sci ; 239: 127-135, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27318757

ABSTRACT

Protein and polysaccharide mixed systems have been actively studied for at least 50years as they can be assembled into functional particles or gels. This article reviews the properties of electrostatic gels, a recently discovered particular case of associative protein-polysaccharide mixtures formed through associative electrostatic interaction under appropriate solution conditions (coupled gel). This review highlights the factors influencing gel formation such as protein-polysaccharide ratio, biopolymer structural characteristics, final pH, ionic strength and total solid concentration. For the first time, the functional properties of protein-polysaccharide coupled gels are presented and discussed in relationship to individual protein and polysaccharide hydrogels. One of their outstanding characteristics is their gel water retention. Up to 600g of water per g of biopolymer may be retained in the electrostatic gel network compared to a protein gel (3-9g of water per g of protein). Potential applications of the gels are proposed to enable the food and non-food industries to develop new functional products with desirable attributes or new interesting materials to incorporate bioactive molecules.


Subject(s)
Hydrogels/chemistry , Polysaccharides/chemistry , Proteins/chemistry , Static Electricity , Animals , Humans
8.
J Phys Chem A ; 119(16): 3689-703, 2015 Apr 23.
Article in English | MEDLINE | ID: mdl-25822662

ABSTRACT

This paper presents a computational study on the low-temperature mechanism and kinetics of the reaction between molecular oxygen and alkyl radicals of methyl propanoate (MP), which plays an important role in low-temperature oxidation and/or autoignition processes of the title fuel. Their multiple reaction pathways either accelerate the oxidation process via chain branching or inhibit it by forming relatively stable products. The potential energy surfaces of the reactions between three primary MP radicals and molecular oxygen, namely, C(•)H2CH2COOCH3 + O2, CH3C(•)HCOOCH3 + O2, and CH3CH2COOC(•)H2 + O2, were constructed using the accurate composite CBS-QB3 method. Thermodynamic properties of all species as well as high-pressure rate constants of all reaction channels were derived with explicit corrections for tunneling and hindered internal rotations. Our calculation results are in good agreement with a limited number of scattered data in the literature. Furthermore, pressure- and temperature-dependent rate constants for all reaction channels on the multiwell-multichannel potential energy surfaces were computed with the quantum Rice-Ramsperger-Kassel (QRRK) and the modified strong collision (MSC) theories. This procedure resulted in a thermodynamically consistent detailed kinetic submechanism for low-temperature oxidation governed by the title process. A simplified mechanism, which consists of important reactions, is also suggested for low-temperature combustion at engine-like conditions.


Subject(s)
Free Radicals/chemistry , Oxygen/chemistry , Propionates/chemistry , Temperature , Kinetics , Oxidation-Reduction , Quantum Theory
9.
Allerg Immunol (Paris) ; 19(9): 369-70, 372, 1987 Nov.
Article in French | MEDLINE | ID: mdl-3453731

ABSTRACT

153 asthmatic children from 5 to 36 months (mean age: 26 months) were investigated. The aim of the study was twofold: 1) to determine the reliability and limits of an allergologic diagnosis before 36 months of age; 2) to compare the predictive value of skin-tests with other allergologic tests. Results were expressed according to a score involving 5 parameters derived from the allergologic investigation. Each parameter represented one point: atopic past history, increased level of total IgE antibodies related to the age, presence of blood specific IgE antibodies, blood hypereosinophilia. Infants were considered allergic if their score level was greater than or equal to 3. Concordance between this score level and each parameter was as follows: Positive skin-test 83%; Blood hypereosinophilia 82%; Presence of specific IgE antibodies 80%; Increased level of total IgE 78%; Familial history of atopy 54%. It is concluded that, in allergic infants, a significative link exists between positive skin-test plus the presence of specific IgE antibodies and an atopic disease. However, more children have to be enrolled in a multivariant analysis to assess definitively the predictive value to this score.


Subject(s)
Asthma/diagnosis , Asthma/etiology , Asthma/genetics , Child, Preschool , Eosinophilia/diagnosis , Female , Humans , Hypersensitivity, Immediate/diagnosis , Immunoglobulin E/analysis , Infant , Male , Radioallergosorbent Test , Skin Tests
10.
Morphol Igazsagugyi Orv Sz ; 18(3): 195-203, 1978 Jul.
Article in Hungarian | MEDLINE | ID: mdl-714058

ABSTRACT

Authors using D.C. (direct current)--have produced shock experimentally- at 28 dogs. In the control animals (8 dogs) no histological, EKG and enzymatic changes could be revealed. In the dogs after the application of D.C of 1 X 2.5 W. sec/kg histological and EKG changes were not revealed, although the level of GOT and CPK increased significantly. After the application of D.C. of 4 X 5 W. sec/kg significant increase of the level of the following enzymes occurred: GOT, isoenzyme- LDH5, total-LDH and CPK. In 7 dogs--out of 8 showing histological changes in the myocard--activity of the serum isoenzyme-LDH1 increased and alterations of the EKG occurred. Thoracic musculature of six experimental dogs was investigated histologically. All of them revealed pathological changes. Correlation between the level of the isoenzyme- LDH1, the histological and EKG alterations were found. Increase of the level of serum enzymes seems to be the consequence of the injury of the thoracic-musculature by D.C. shock, and has clinical significance only in cases when pathologic changes of the EKG and increase of the insoenzyme-LDH1 are also present.


Subject(s)
Electroshock , Myocardium/enzymology , Animals , Dogs , Electrocardiography , Enzymes/blood , Heart/physiology , Muscles/enzymology , Muscles/pathology , Myocardium/pathology , Thorax/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...