It is complicated to model the acoustic field in stratified ocean for airborne aircraft,due to high speed of the source and air-to-water sound transmission.To our knowledge,there are very few papers in the open litera...It is complicated to model the acoustic field in stratified ocean for airborne aircraft,due to high speed of the source and air-to-water sound transmission.To our knowledge,there are very few papers in the open literature dealing with this complicated problem;but,in our opinion,they all require great amount of computation.We now propose a different method that requires much less computation.We improve the wavenumber integration method to model the received temporal signal for a moving source in stratified ocean and sum up in a concise form the core of our paper as follows:(A) Eq.(11) can be calculated by means of fast Chirp Z transform and the signals at all N time points are generated simultaneously;(B) direct numerical evaluation of the wavenumber integral in Eq.(4) produces large numerical errors;so it is necessary to shift the integration slightly below the real axis;(C) we compare the computation cost of direct calculation method with that of our fast calculation method;from the results presented in table 1,we can see that the fast calculation method consumes much less computation time,particularly for long duration signals;(D) for an airborne rapidly moving source,we compute the Doppler-shifted signals in shallow water and analyze their short-time Fourier transform;from Fig.1b,we can see that the received signals have multiple frequency components for a tonal source due to source motion and that each component corresponds to an arrival path.展开更多
为解决含氢综合能源系统(hydrogen integrated energy system,HIES)在源荷出力和场景概率多重不确定性下难以兼顾鲁棒性和经济性的问题,提出了一种计及场景概率的分布鲁棒和两阶段鲁棒结合的三阶段四层随机鲁棒优化方法。首先,充分考虑...为解决含氢综合能源系统(hydrogen integrated energy system,HIES)在源荷出力和场景概率多重不确定性下难以兼顾鲁棒性和经济性的问题,提出了一种计及场景概率的分布鲁棒和两阶段鲁棒结合的三阶段四层随机鲁棒优化方法。首先,充分考虑系统运行的灵活性、低碳性,建立HIES,并引入碳捕集机组和阶梯式碳交易保证系统低碳运行;其次,用鲁棒优化法和随机规划中的场景法分别处理源荷出力不确定和场景概率不确定,建立min-max-max-min三阶段四层优化模型。采用变量交替迭代的列与约束生成算法求解得到最优鲁棒调度结果以及最恶劣场景概率分布。最后,通过算例分析表明所提方法兼顾了经济性和鲁棒性,并且系统具有较强的新能源消纳能力,保证了HIES系统的低碳、经济运行。展开更多
文摘It is complicated to model the acoustic field in stratified ocean for airborne aircraft,due to high speed of the source and air-to-water sound transmission.To our knowledge,there are very few papers in the open literature dealing with this complicated problem;but,in our opinion,they all require great amount of computation.We now propose a different method that requires much less computation.We improve the wavenumber integration method to model the received temporal signal for a moving source in stratified ocean and sum up in a concise form the core of our paper as follows:(A) Eq.(11) can be calculated by means of fast Chirp Z transform and the signals at all N time points are generated simultaneously;(B) direct numerical evaluation of the wavenumber integral in Eq.(4) produces large numerical errors;so it is necessary to shift the integration slightly below the real axis;(C) we compare the computation cost of direct calculation method with that of our fast calculation method;from the results presented in table 1,we can see that the fast calculation method consumes much less computation time,particularly for long duration signals;(D) for an airborne rapidly moving source,we compute the Doppler-shifted signals in shallow water and analyze their short-time Fourier transform;from Fig.1b,we can see that the received signals have multiple frequency components for a tonal source due to source motion and that each component corresponds to an arrival path.
文摘为解决含氢综合能源系统(hydrogen integrated energy system,HIES)在源荷出力和场景概率多重不确定性下难以兼顾鲁棒性和经济性的问题,提出了一种计及场景概率的分布鲁棒和两阶段鲁棒结合的三阶段四层随机鲁棒优化方法。首先,充分考虑系统运行的灵活性、低碳性,建立HIES,并引入碳捕集机组和阶梯式碳交易保证系统低碳运行;其次,用鲁棒优化法和随机规划中的场景法分别处理源荷出力不确定和场景概率不确定,建立min-max-max-min三阶段四层优化模型。采用变量交替迭代的列与约束生成算法求解得到最优鲁棒调度结果以及最恶劣场景概率分布。最后,通过算例分析表明所提方法兼顾了经济性和鲁棒性,并且系统具有较强的新能源消纳能力,保证了HIES系统的低碳、经济运行。
