针对基于802.11p的车载自组织网络(VANET,Vehicular Ad hoc Network)的吞吐量最优化问题,采用启发式搜索优化的思想,在数据传输方面提出了改进的搜索者优化算法(ISOA,Improved Seeker Optimization Algorithm)。该算法通过对节点发送概...针对基于802.11p的车载自组织网络(VANET,Vehicular Ad hoc Network)的吞吐量最优化问题,采用启发式搜索优化的思想,在数据传输方面提出了改进的搜索者优化算法(ISOA,Improved Seeker Optimization Algorithm)。该算法通过对节点发送概率的最优化实现节点平均吞吐量的最大化;通过对吞吐量变化的检测调整发送概率,实现对通信环境变化的自适应性;通过对在VANET场景下传统SOA的改进,提高了搜索全局最优解的成功率。仿真结果表明,ISOA较传统算法在环境变化自适应性方面更好,在收敛速度及准确度等方面性能也更优。展开更多
Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical...Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical nature of surface and the preparation of new catalyst. The production of R 3 Sn-O-MCM-41 (R 3 SnM) was obtained by heating tributyltin chloride and Al-MCM-41 mixture at 170 °C for 5 h under stirring in nitrogen atmosphere. The composition, structure and surface physical and chemical properties of the samples were characterized by inductively coupled plasma mass spectrometry (ICP-MS), 13 C, 119 Sn, 29 Si and 27 Al solid state NMR (nuclear magnetic resonance) spectra, in-situ pyridine infrared spectroscopy (Py-IR), N 2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), etc. The results of ICP and organic elemental analysis shows that the grafting yield w Sn was 6.46% for R 3 SnM. H 0 (the negative logarithm of the acid concentration)and the number of acid sites for R 3 SnM respectively were 2.77-0.99 and 4.8 mmol·g-1 by the Hammett method. N 2 adsorption-desorption, XRD, TEM analysis showed that R 3 SnM with ordered hexagonal mesopore structure, resulted in the decease of surface areas and pore size as well as the increase of mesoporous volume and surface acidity, as compared to Al-MCM-41. R 3 SnM was used in the synthesis of isoamyl acetate. The yield of isoamyl acetate was 96% when n(isoamyl alcohol)︰n(acetic acid) 1.0︰1.0, 3 R SnM w 5%, 138 °C for 5 h. The catalyst can be reused and the yield of 86% can be attained when catalyst was reused five times at the same catalytic conditions.展开更多
Recently,bio-inspired algorithms have been increasingly explored for autonomous robot path planning on grid-based maps.However,these approaches endure performance degradation as problem complexity increases,often resu...Recently,bio-inspired algorithms have been increasingly explored for autonomous robot path planning on grid-based maps.However,these approaches endure performance degradation as problem complexity increases,often resulting in lengthy search times to find an optimal solution.This limitation is particularly critical for real-world applications like autonomous off-road vehicles,where highquality path computation is essential for energy efficiency.To address these challenges,this paper proposes a new graph-based optimal path planning approach that leverages a sort of bio-inspired algorithm,improved seagull optimization algorithm(iSOA)for rapid path planning of autonomous robots.A modified Douglas–Peucker(mDP)algorithm is developed to approximate irregular obstacles as polygonal obstacles based on the environment image in rough terrains.The resulting mDPderived graph is then modeled using a Maklink graph theory.By applying the iSOA approach,the trajectory of an autonomous robot in the workspace is optimized.Additionally,a Bezier-curve-based smoothing approach is developed to generate safer and smoother trajectories while adhering to curvature constraints.The proposed model is validated through simulated experiments undertaken in various real-world settings,and its performance is compared with state-of-the-art algorithms.The experimental results demonstrate that the proposed model outperforms existing approaches in terms of time cost and path length.展开更多
文摘针对基于802.11p的车载自组织网络(VANET,Vehicular Ad hoc Network)的吞吐量最优化问题,采用启发式搜索优化的思想,在数据传输方面提出了改进的搜索者优化算法(ISOA,Improved Seeker Optimization Algorithm)。该算法通过对节点发送概率的最优化实现节点平均吞吐量的最大化;通过对吞吐量变化的检测调整发送概率,实现对通信环境变化的自适应性;通过对在VANET场景下传统SOA的改进,提高了搜索全局最优解的成功率。仿真结果表明,ISOA较传统算法在环境变化自适应性方面更好,在收敛速度及准确度等方面性能也更优。
基金Supported by the National Science Foundation of Heilongjiang Province (B201010)the Education Department of Heilongjiang Province (12511595)
文摘Surface organometallic chemistry (SOMC) is a recently developing research field. It is of great significance for the quantitative modification, restoration of solid surface, identification of the physical and chemical nature of surface and the preparation of new catalyst. The production of R 3 Sn-O-MCM-41 (R 3 SnM) was obtained by heating tributyltin chloride and Al-MCM-41 mixture at 170 °C for 5 h under stirring in nitrogen atmosphere. The composition, structure and surface physical and chemical properties of the samples were characterized by inductively coupled plasma mass spectrometry (ICP-MS), 13 C, 119 Sn, 29 Si and 27 Al solid state NMR (nuclear magnetic resonance) spectra, in-situ pyridine infrared spectroscopy (Py-IR), N 2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), etc. The results of ICP and organic elemental analysis shows that the grafting yield w Sn was 6.46% for R 3 SnM. H 0 (the negative logarithm of the acid concentration)and the number of acid sites for R 3 SnM respectively were 2.77-0.99 and 4.8 mmol·g-1 by the Hammett method. N 2 adsorption-desorption, XRD, TEM analysis showed that R 3 SnM with ordered hexagonal mesopore structure, resulted in the decease of surface areas and pore size as well as the increase of mesoporous volume and surface acidity, as compared to Al-MCM-41. R 3 SnM was used in the synthesis of isoamyl acetate. The yield of isoamyl acetate was 96% when n(isoamyl alcohol)︰n(acetic acid) 1.0︰1.0, 3 R SnM w 5%, 138 °C for 5 h. The catalyst can be reused and the yield of 86% can be attained when catalyst was reused five times at the same catalytic conditions.
文摘Recently,bio-inspired algorithms have been increasingly explored for autonomous robot path planning on grid-based maps.However,these approaches endure performance degradation as problem complexity increases,often resulting in lengthy search times to find an optimal solution.This limitation is particularly critical for real-world applications like autonomous off-road vehicles,where highquality path computation is essential for energy efficiency.To address these challenges,this paper proposes a new graph-based optimal path planning approach that leverages a sort of bio-inspired algorithm,improved seagull optimization algorithm(iSOA)for rapid path planning of autonomous robots.A modified Douglas–Peucker(mDP)algorithm is developed to approximate irregular obstacles as polygonal obstacles based on the environment image in rough terrains.The resulting mDPderived graph is then modeled using a Maklink graph theory.By applying the iSOA approach,the trajectory of an autonomous robot in the workspace is optimized.Additionally,a Bezier-curve-based smoothing approach is developed to generate safer and smoother trajectories while adhering to curvature constraints.The proposed model is validated through simulated experiments undertaken in various real-world settings,and its performance is compared with state-of-the-art algorithms.The experimental results demonstrate that the proposed model outperforms existing approaches in terms of time cost and path length.
基金Supported by Scientific research project of traditional Chinese medicine of Hubei Province in 2014,research project at the academy level of Hubei Provincial Hospital of TCM:JDZX2014Y06
