A new singularity extraction technique is presented to calculate accurately the singular integrals in Time Domain Electric Field Integral Equation (TDEFIE).In singularity extraction pro- cedure,through the aid of the ...A new singularity extraction technique is presented to calculate accurately the singular integrals in Time Domain Electric Field Integral Equation (TDEFIE).In singularity extraction pro- cedure,through the aid of the first order Taylor series of time base function including time-retardation,the singularity of the integrand can be removed.The surface current density and backscattered far-field response of a conducting cube illuminated by a Gaussian plane wave is com- puted using the presented technique.Comparisons are made with the results obtained by the Inverse Discrete Fourier Transform (IDFT) of the frequency domain and the results obtained by using Ve- chinski's time averaging technique,which demonstrate that the presented method with this new time domain singularity extraction technique to solve TDEFIE is very accurate and stable.展开更多
As a result of recent accidents, society is becoming more conscious and concerned about the risk that are under to the environment and communities. A proposal of assessment of the vulnerability of the environment and ...As a result of recent accidents, society is becoming more conscious and concerned about the risk that are under to the environment and communities. A proposal of assessment of the vulnerability of the environment and community is presented here under a holistic perspective using fuzzy logic as a formal tool. An internal factor of the risk of a system under a given threat is assessed. Risk is considered as the union between the threat and the vulnerability of the environment and community. This approach shows that the reduction in either or both of them makes a reduction in the risk content as well. The main purpose of this proposal is not to obtain a single value as output; in fact the result is a map which can contribute to the different areas of the community in decision making.展开更多
文摘A new singularity extraction technique is presented to calculate accurately the singular integrals in Time Domain Electric Field Integral Equation (TDEFIE).In singularity extraction pro- cedure,through the aid of the first order Taylor series of time base function including time-retardation,the singularity of the integrand can be removed.The surface current density and backscattered far-field response of a conducting cube illuminated by a Gaussian plane wave is com- puted using the presented technique.Comparisons are made with the results obtained by the Inverse Discrete Fourier Transform (IDFT) of the frequency domain and the results obtained by using Ve- chinski's time averaging technique,which demonstrate that the presented method with this new time domain singularity extraction technique to solve TDEFIE is very accurate and stable.
文摘As a result of recent accidents, society is becoming more conscious and concerned about the risk that are under to the environment and communities. A proposal of assessment of the vulnerability of the environment and community is presented here under a holistic perspective using fuzzy logic as a formal tool. An internal factor of the risk of a system under a given threat is assessed. Risk is considered as the union between the threat and the vulnerability of the environment and community. This approach shows that the reduction in either or both of them makes a reduction in the risk content as well. The main purpose of this proposal is not to obtain a single value as output; in fact the result is a map which can contribute to the different areas of the community in decision making.
