In the present paper, Charpy impact resistance of aluminum-epoxy laminated composites in both crack divider and crack ar-rester configurations has been investigated. In both configurations, an analytical investigation...In the present paper, Charpy impact resistance of aluminum-epoxy laminated composites in both crack divider and crack ar-rester configurations has been investigated. In both configurations, an analytical investigation has been carried out to evaluate the effects of layers thickness on impact resistance of the specimens. A model based on fuzzy logic for predicting impact re-sistance of the specimens has been presented. For purpose of building the model, training and testing using experimental re-sults from 126 specimens produced from two basic composites were conducted. The data used for the input data in fuzzy logic models are arranged in a format of 7 input parameters that cover the thickness of layers, the number of layers, the adhesive type, the crack tip configuration, the content of SiC particles, the content of methacrylated butadiene-styrene particles and the number of test trial. According to these input parameters, in the fuzzy logic model, the impact resistance of each specimen was predicted. The training and testing results in the fuzzy logic model have shown a strong potential for predicting impact resis-tance of aluminum-epoxy laminated composites.展开更多
Human immunodeficiency virus （HIV） emerged as one of the most serious health issues of the modern era. Till date, it challenges the scientists working in the fields related to its prevention, least spread and eradic...Human immunodeficiency virus （HIV） emerged as one of the most serious health issues of the modern era. Till date, it challenges the scientists working in the fields related to its prevention, least spread and eradication. It affects not only the person suffering from it but also the communities and their economies. Mathematical modeling is one of the ways to explore the possibilities of prediction （and control） strategies for contagious deceases. In this paper, we have tried to extend the scope of a currently available prediction model for a continuous time span. For this purpose, an analytical investigation of the system of nonlinear differential equations, governing the HIV infection of CD4 ＋ T-cells, is carried out. A new emerging analytical technique Optimal Variational Iteration Method （OVIM） has been used to obtain an analytical and convergent solution. Analytical solutions are continuous solutions that can be used to predict the phenomena without the involvement of interpolation or extrapolation errors. On the other hand, their use in the derived equations, depending upon solution itself, is far easier than the numerical solutions. We have presented the error analysis and the prediction curves graphically. Moreover, a comparison with traditional Variational Iteration is also provided. It is concluded that the traditional method fails to converge for the updated models which involve the delayed differential equations.展开更多
文摘In the present paper, Charpy impact resistance of aluminum-epoxy laminated composites in both crack divider and crack ar-rester configurations has been investigated. In both configurations, an analytical investigation has been carried out to evaluate the effects of layers thickness on impact resistance of the specimens. A model based on fuzzy logic for predicting impact re-sistance of the specimens has been presented. For purpose of building the model, training and testing using experimental re-sults from 126 specimens produced from two basic composites were conducted. The data used for the input data in fuzzy logic models are arranged in a format of 7 input parameters that cover the thickness of layers, the number of layers, the adhesive type, the crack tip configuration, the content of SiC particles, the content of methacrylated butadiene-styrene particles and the number of test trial. According to these input parameters, in the fuzzy logic model, the impact resistance of each specimen was predicted. The training and testing results in the fuzzy logic model have shown a strong potential for predicting impact resis-tance of aluminum-epoxy laminated composites.
文摘Human immunodeficiency virus （HIV） emerged as one of the most serious health issues of the modern era. Till date, it challenges the scientists working in the fields related to its prevention, least spread and eradication. It affects not only the person suffering from it but also the communities and their economies. Mathematical modeling is one of the ways to explore the possibilities of prediction （and control） strategies for contagious deceases. In this paper, we have tried to extend the scope of a currently available prediction model for a continuous time span. For this purpose, an analytical investigation of the system of nonlinear differential equations, governing the HIV infection of CD4 ＋ T-cells, is carried out. A new emerging analytical technique Optimal Variational Iteration Method （OVIM） has been used to obtain an analytical and convergent solution. Analytical solutions are continuous solutions that can be used to predict the phenomena without the involvement of interpolation or extrapolation errors. On the other hand, their use in the derived equations, depending upon solution itself, is far easier than the numerical solutions. We have presented the error analysis and the prediction curves graphically. Moreover, a comparison with traditional Variational Iteration is also provided. It is concluded that the traditional method fails to converge for the updated models which involve the delayed differential equations.
