Recently, we found that side lobes of wavelets have a large impact on the identification of thin sand reservoirs when studying some gas fields in a basin in Northwest China. Reflections from the top of the H Formation...Recently, we found that side lobes of wavelets have a large impact on the identification of thin sand reservoirs when studying some gas fields in a basin in Northwest China. Reflections from the top of the H Formation, in which there are gas-bearing thin sand bodies, have the main wavelet lobe between two weak peak side lobes. The lower one always mixes with another peak reflected from the top of a thin sand reservoir. That makes it difficult to identify the sand reservoir. In order to solve this, many forward models were set up using typical well logs. 2D synthetic profiles were produced using Ricker wavelets to study the relationships between the effects of wavelet side lobes and thin sand position and frequency and between amplitude and the thin sand body. We developed the following conclusions： First, it is easier to identify thin sands in a shallower position. Second, a good way to tell sand body reflections from side lobes is by comparing profiles with different frequency windows. Third, it is helpful and effective to describe sand extent using amplitude attributes.展开更多
A hybrid method for synthesizing antenna＇s three dimensional （3D） pattern is proposed to obtain the low sidelobe feature of truncated cone conformal phased arrays. In this method, the elements of truncated cone con...A hybrid method for synthesizing antenna＇s three dimensional （3D） pattern is proposed to obtain the low sidelobe feature of truncated cone conformal phased arrays. In this method, the elements of truncated cone conformal phased arrays are projected to the tangent plane in one generatrix of the truncated cone. Then two dimensional （2D） Chebyshev amplitude distribution optimization is respectively used in two mutual vertical directions of the tangent plane. According to the location of the elements, the excitation current amplitude distribution of each element on the conformal structure is derived reversely, then the excitation current amplitude is further optimized by using the genetic algorithm （GA）. A truncated cone problem with 8x8 elements on it, and a 3D pattern desired side lobe level （SLL） up to 35 dB, is studied. By using the hybrid method, the optimal goal is accomplished with acceptable CPU time, which indicates that this hybrid method for the low sidelobe synthesis is feasible.展开更多
Purpose-The purpose of this paper is to improve energy efficiency and further reduction of side lobe level the algorithm proposed is firework algorithm.In this paper,roused by the eminent swarm conduct of firecrackers...Purpose-The purpose of this paper is to improve energy efficiency and further reduction of side lobe level the algorithm proposed is firework algorithm.In this paper,roused by the eminent swarm conduct of firecrackers,a novel multitude insight calculation called fireworks algorithm(FA)is proposed for work enhancement.The FA is introduced and actualized by mimicking the blast procedure of firecrackers.In the FA,two blast(search)forms are utilized and systems for keeping decent variety of sparkles are likewise all around planned.To approve the presentation of the proposed FA,correlation tests were led on nine benchmark test capacities among the FA,the standard PSO(SPSO)and the clonal PSO(CPSO).Design/methodology/approach-The antenna arrays are used to improve the capacity and spectral efficiency of wireless communication system.The latest communication systems use the antenna array technology to improve the spectral efficiency,fill rate and the energy efficiency of the communication system can be enhanced.One of the most important properties of antenna array is beam pattern.A directional main lobe with low side lobe level(SLL)of the beam pattern will reduce the interference and enhance the quality of communication.The classical methods for reducing the side lobe level are differential evolution algorithm and PSO algorithm.In this paper,roused by the eminent swarm conduct of firecrackers,a novel multitude insight calculation called fireworks algorithm(FA)is proposed for work enhancement.The FA is introduced and actualized by mimicking the blast procedure of firecrackers.In the FA,two blast(search)forms are utilized and systems for keeping decent variety of sparkles are likewise all around planned.To approve the presentation of the proposed FA,correlation tests were led on nine benchmark test capacities among the FA,the standard PSO(SPSO)and the clonal PSO(CPSO).It is demonstrated that the FA plainly beats the SPSO and the CPSO in both enhancement exactness and combination speed.The results convey that the side lobe level is reduced to34.78dB and fill rate is increased to 78.53.Findings-Samples including 16-element LAAs are conducted to verify the optimization performances of the SLL reductions.Simulation results show that the SLLs can be effectively reduced by FA.Moreover,compared with other benchmark algorithms,fireworks has a better performance in terms of the accuracy,the convergence rate and the stability.Research limitations/implications-With the use of algorithms radiation is prone to noise one way or other.Even with any optimizations we cannot expect radiation to be ideal.Power dissipation or electro magnetic interference is bound to happen,but the use of optimization algorithms tries to reduce them to the extent that is possible.Practical implications-16-element linear antenna array is available with latest versions of Matlab.Social implications-The latest technologies and emerging developments in the field of communication and with exponential growth in users the capacity of communication system has bottlenecks.The antenna arrays are used to improve the capacity and spectral efficiency of wireless communication system.The latest communication systems use the antenna array technology which is to improve the spectral efficiency,fill rate and the energy efficiency of the communication system can be enhanced.Originality/value-By using FA,the fill rate is increased to 78.53 and the side lobe level is reduced to 35dB,when compared with the bench mark algorithms.展开更多
Side lobe level reduction(SLL)of antenna arrays significantly enhances the signal-to-interference ratio and improves the quality of service(QOS)in recent and future wireless communication systems starting from 5G up t...Side lobe level reduction(SLL)of antenna arrays significantly enhances the signal-to-interference ratio and improves the quality of service(QOS)in recent and future wireless communication systems starting from 5G up to 7G.Furthermore,it improves the array gain and directivity,increasing the detection range and angular resolution of radar systems.This study proposes two highly efficient SLL reduction techniques.These techniques are based on the hybridization between either the single convolution or the double convolution algorithms and the genetic algorithm(GA)to develop the Conv/GA andDConv/GA,respectively.The convolution process determines the element’s excitations while the GA optimizes the element spacing.For M elements linear antenna array(LAA),the convolution of the excitation coefficients vector by itself provides a new vector of excitations of length N=(2M−1).This new vector is divided into three different sets of excitations including the odd excitations,even excitations,and middle excitations of lengths M,M−1,andM,respectively.When the same element spacing as the original LAA is used,it is noticed that the odd and even excitations provide a much lower SLL than that of the LAA but with amuch wider half-power beamwidth(HPBW).While the middle excitations give the same HPBWas the original LAA with a relatively higher SLL.Tomitigate the increased HPBWof the odd and even excitations,the element spacing is optimized using the GA.Thereby,the synthesized arrays have the same HPBW as the original LAA with a two-fold reduction in the SLL.Furthermore,for extreme SLL reduction,the DConv/GA is introduced.In this technique,the same procedure of the aforementioned Conv/GA technique is performed on the resultant even and odd excitation vectors.It provides a relatively wider HPBWthan the original LAA with about quad-fold reduction in the SLL.展开更多
文摘Recently, we found that side lobes of wavelets have a large impact on the identification of thin sand reservoirs when studying some gas fields in a basin in Northwest China. Reflections from the top of the H Formation, in which there are gas-bearing thin sand bodies, have the main wavelet lobe between two weak peak side lobes. The lower one always mixes with another peak reflected from the top of a thin sand reservoir. That makes it difficult to identify the sand reservoir. In order to solve this, many forward models were set up using typical well logs. 2D synthetic profiles were produced using Ricker wavelets to study the relationships between the effects of wavelet side lobes and thin sand position and frequency and between amplitude and the thin sand body. We developed the following conclusions： First, it is easier to identify thin sands in a shallower position. Second, a good way to tell sand body reflections from side lobes is by comparing profiles with different frequency windows. Third, it is helpful and effective to describe sand extent using amplitude attributes.
基金supported by the Fundamental Research Funds for the Central Universities(YWF-13D2-XX-13)the National High-tech Research and Development Program(863 Program)(2008AA121802)
文摘A hybrid method for synthesizing antenna＇s three dimensional （3D） pattern is proposed to obtain the low sidelobe feature of truncated cone conformal phased arrays. In this method, the elements of truncated cone conformal phased arrays are projected to the tangent plane in one generatrix of the truncated cone. Then two dimensional （2D） Chebyshev amplitude distribution optimization is respectively used in two mutual vertical directions of the tangent plane. According to the location of the elements, the excitation current amplitude distribution of each element on the conformal structure is derived reversely, then the excitation current amplitude is further optimized by using the genetic algorithm （GA）. A truncated cone problem with 8x8 elements on it, and a 3D pattern desired side lobe level （SLL） up to 35 dB, is studied. By using the hybrid method, the optimal goal is accomplished with acceptable CPU time, which indicates that this hybrid method for the low sidelobe synthesis is feasible.
文摘Purpose-The purpose of this paper is to improve energy efficiency and further reduction of side lobe level the algorithm proposed is firework algorithm.In this paper,roused by the eminent swarm conduct of firecrackers,a novel multitude insight calculation called fireworks algorithm(FA)is proposed for work enhancement.The FA is introduced and actualized by mimicking the blast procedure of firecrackers.In the FA,two blast(search)forms are utilized and systems for keeping decent variety of sparkles are likewise all around planned.To approve the presentation of the proposed FA,correlation tests were led on nine benchmark test capacities among the FA,the standard PSO(SPSO)and the clonal PSO(CPSO).Design/methodology/approach-The antenna arrays are used to improve the capacity and spectral efficiency of wireless communication system.The latest communication systems use the antenna array technology to improve the spectral efficiency,fill rate and the energy efficiency of the communication system can be enhanced.One of the most important properties of antenna array is beam pattern.A directional main lobe with low side lobe level(SLL)of the beam pattern will reduce the interference and enhance the quality of communication.The classical methods for reducing the side lobe level are differential evolution algorithm and PSO algorithm.In this paper,roused by the eminent swarm conduct of firecrackers,a novel multitude insight calculation called fireworks algorithm(FA)is proposed for work enhancement.The FA is introduced and actualized by mimicking the blast procedure of firecrackers.In the FA,two blast(search)forms are utilized and systems for keeping decent variety of sparkles are likewise all around planned.To approve the presentation of the proposed FA,correlation tests were led on nine benchmark test capacities among the FA,the standard PSO(SPSO)and the clonal PSO(CPSO).It is demonstrated that the FA plainly beats the SPSO and the CPSO in both enhancement exactness and combination speed.The results convey that the side lobe level is reduced to34.78dB and fill rate is increased to 78.53.Findings-Samples including 16-element LAAs are conducted to verify the optimization performances of the SLL reductions.Simulation results show that the SLLs can be effectively reduced by FA.Moreover,compared with other benchmark algorithms,fireworks has a better performance in terms of the accuracy,the convergence rate and the stability.Research limitations/implications-With the use of algorithms radiation is prone to noise one way or other.Even with any optimizations we cannot expect radiation to be ideal.Power dissipation or electro magnetic interference is bound to happen,but the use of optimization algorithms tries to reduce them to the extent that is possible.Practical implications-16-element linear antenna array is available with latest versions of Matlab.Social implications-The latest technologies and emerging developments in the field of communication and with exponential growth in users the capacity of communication system has bottlenecks.The antenna arrays are used to improve the capacity and spectral efficiency of wireless communication system.The latest communication systems use the antenna array technology which is to improve the spectral efficiency,fill rate and the energy efficiency of the communication system can be enhanced.Originality/value-By using FA,the fill rate is increased to 78.53 and the side lobe level is reduced to 35dB,when compared with the bench mark algorithms.
基金Research Supporting Project Number(RSPD2023R 585),King Saud University,Riyadh,Saudi Arabia.
文摘Side lobe level reduction(SLL)of antenna arrays significantly enhances the signal-to-interference ratio and improves the quality of service(QOS)in recent and future wireless communication systems starting from 5G up to 7G.Furthermore,it improves the array gain and directivity,increasing the detection range and angular resolution of radar systems.This study proposes two highly efficient SLL reduction techniques.These techniques are based on the hybridization between either the single convolution or the double convolution algorithms and the genetic algorithm(GA)to develop the Conv/GA andDConv/GA,respectively.The convolution process determines the element’s excitations while the GA optimizes the element spacing.For M elements linear antenna array(LAA),the convolution of the excitation coefficients vector by itself provides a new vector of excitations of length N=(2M−1).This new vector is divided into three different sets of excitations including the odd excitations,even excitations,and middle excitations of lengths M,M−1,andM,respectively.When the same element spacing as the original LAA is used,it is noticed that the odd and even excitations provide a much lower SLL than that of the LAA but with amuch wider half-power beamwidth(HPBW).While the middle excitations give the same HPBWas the original LAA with a relatively higher SLL.Tomitigate the increased HPBWof the odd and even excitations,the element spacing is optimized using the GA.Thereby,the synthesized arrays have the same HPBW as the original LAA with a two-fold reduction in the SLL.Furthermore,for extreme SLL reduction,the DConv/GA is introduced.In this technique,the same procedure of the aforementioned Conv/GA technique is performed on the resultant even and odd excitation vectors.It provides a relatively wider HPBWthan the original LAA with about quad-fold reduction in the SLL.
