This paper studies the effect of amplitude-phase errors on the antenna performance. Via builting on a worst-case error tolerance model, a simple and practical worst error tolerance analysis based on the chaos-genetic ...This paper studies the effect of amplitude-phase errors on the antenna performance. Via builting on a worst-case error tolerance model, a simple and practical worst error tolerance analysis based on the chaos-genetic algorithm （CGA） is proposed. The proposed method utilizes chaos to optimize initial population for the genetic algorithm （GA） and introduces chaotic disturbance into the genetic mutation, thereby improving the ability of the GA to search for the global optimum. Numerical simulations demonstrate that the accuracy and stability of the worst-case analysis of the proposed approach are superior to the GA. And the proposed algorithm can be used easily for the error tolerant design of antenna arrays.展开更多
Herein,we present a thermo-mechanical analyzer(TMA)and dynamic mechanical analyzer(DMA)of composite multi-layered gun propellant,focusing on thermal expansion coefficients and dynamic thermomechanical properties.The l...Herein,we present a thermo-mechanical analyzer(TMA)and dynamic mechanical analyzer(DMA)of composite multi-layered gun propellant,focusing on thermal expansion coefficients and dynamic thermomechanical properties.The linear thermal expansion coefficient of the prepared energetic material is determined as approx.0.1800×10^(-4)-0.2081×10^(-4)K^(-1).According to DMA test and dynamic thermomechanical properties,the glass transition temperature is also obtained.The tested value is within the range of 223.01-223.50 K,which indicates the lower limit of the energetic material.However,DMA tests reveal temperature changes,which occur due to thermal expansion.Moreover,the geometrical factor decreases with increasing temperature.Therefore,thermal expansion significantly affects the storage modulus and loss modulus.Additionally,the thermal expansion coefficient can be used to modify the storage and loss modulus.The results show that the proposed method provides effective and reliable modified results.展开更多
基金supported by the National Natural Science Foundation of China (60901055)
文摘This paper studies the effect of amplitude-phase errors on the antenna performance. Via builting on a worst-case error tolerance model, a simple and practical worst error tolerance analysis based on the chaos-genetic algorithm （CGA） is proposed. The proposed method utilizes chaos to optimize initial population for the genetic algorithm （GA） and introduces chaotic disturbance into the genetic mutation, thereby improving the ability of the GA to search for the global optimum. Numerical simulations demonstrate that the accuracy and stability of the worst-case analysis of the proposed approach are superior to the GA. And the proposed algorithm can be used easily for the error tolerant design of antenna arrays.
文摘Herein,we present a thermo-mechanical analyzer(TMA)and dynamic mechanical analyzer(DMA)of composite multi-layered gun propellant,focusing on thermal expansion coefficients and dynamic thermomechanical properties.The linear thermal expansion coefficient of the prepared energetic material is determined as approx.0.1800×10^(-4)-0.2081×10^(-4)K^(-1).According to DMA test and dynamic thermomechanical properties,the glass transition temperature is also obtained.The tested value is within the range of 223.01-223.50 K,which indicates the lower limit of the energetic material.However,DMA tests reveal temperature changes,which occur due to thermal expansion.Moreover,the geometrical factor decreases with increasing temperature.Therefore,thermal expansion significantly affects the storage modulus and loss modulus.Additionally,the thermal expansion coefficient can be used to modify the storage and loss modulus.The results show that the proposed method provides effective and reliable modified results.
