In this paper, we develop a new theoretical framework by means of the absorbing Markov process theory for analyzing some stochastic global optimization algorithms. Applying the framework to the pure random search, we ...In this paper, we develop a new theoretical framework by means of the absorbing Markov process theory for analyzing some stochastic global optimization algorithms. Applying the framework to the pure random search, we prove that the pure random search converges to the global minimum in probability and its time has geometry distribution. We also analyze the pure adaptive search by this framework and turn out that the pure adaptive search converges to the global minimum in probability and its time has Poisson distribution.展开更多
Rankine source method,optimization technology,parametric modeling technology,and improved multiobjective optimization algorithm were combined to investigate the multiobjective optimization design of hull form.A multio...Rankine source method,optimization technology,parametric modeling technology,and improved multiobjective optimization algorithm were combined to investigate the multiobjective optimization design of hull form.A multiobjective and multilevel optimization design framework was constructed for the comprehensive navigation performance of ships.CAESES software was utilized as the optimization platform,and nondominated sorting genetic algorithm II(NSGA-II)was used to conduct multiobjective optimization research on the resistance and sea-keeping performance of the ITTC Ship A-2 fishing vessel.Optimization objectives of this study are heave/pitch response amplitude and wave-making resistance.Taking the displacement and the length between perpendiculars as constraints,we optimized the profile of the hull.Analytic hierarchy process(AHP)and technique for order preference by similarity to ideal solution(TOPSIS)were used to sort and select Pareto solutions and determine weight coefficient of each navigation performance objective in the general objective.Finally,the hydrodynamic performance before and after the parametric deformation of the hull was compared.The results show that both the wave-making resistance and heave/pitch amplitude of the optimized hull form are reduced,and the satisfactory optimal hull form is obtained.The results of this study have a certain reference value for the initial stage of multiobjective optimization design of hull form.展开更多
Based on the trajectory design of a mission to Saturn, this paper discusses four different trajectories in various swingby cases. We assume a single impulse to be applied in each case when the spacecraft approaches a ...Based on the trajectory design of a mission to Saturn, this paper discusses four different trajectories in various swingby cases. We assume a single impulse to be applied in each case when the spacecraft approaches a celestial body. Some optimal trajectories ofEJS, EMS, EVEJS and EVVEJS flying sequences are obtained using five global optimization algorithms： DE, PSO, DP, the hybrid algorithm PSODE and another hybrid algorithm, DPDE. DE is proved to be supe- rior to other non-hybrid algorithms in the trajectory optimi- zation problem. The hybrid algorithm of PSO and DE can improve the optimization performance of DE, which is vali- dated by the mission to Saturn with given swingby sequences. Finally, the optimization results of four different swingby sequences are compared with those of the ACT of ESA.展开更多
This paper presents a new stochastic algorithm for box constrained global optimization problem. Bacause the level set of objective function is always not known, the authors designed a region containing the current mi...This paper presents a new stochastic algorithm for box constrained global optimization problem. Bacause the level set of objective function is always not known, the authors designed a region containing the current minimum point to replace it, and in order to fit the level set well, this region would be walking and contracting in the running process. Thus, the new algorithm is named as region's walk and contraction(RWC). Some numerical experiments for the RWC were conducted, which indicate good property of the algorithm.展开更多
In this study,we consider the global optimization problem in a hypercube.We use a class of series to construct a curve in a hypercube,which can fill the hypercube,and we present an integral function on the curve.Based...In this study,we consider the global optimization problem in a hypercube.We use a class of series to construct a curve in a hypercube,which can fill the hypercube,and we present an integral function on the curve.Based on the integral function,we propose an algorithm for solving the global optimization problem.Then,we perform a convergence analysis and numerical experiments to demonstrate the effectiveness of the proposed algorithm.展开更多
In this paper, the improvement of pure random search is studied. By taking some information of the function to be minimized into consideration, the authors propose two stochastic global optimization algorithms. Some n...In this paper, the improvement of pure random search is studied. By taking some information of the function to be minimized into consideration, the authors propose two stochastic global optimization algorithms. Some numerical experiments for the new stochastic global optimization algorithms are presented for a class of test problems.展开更多
Two-dimensional(2D)fully compensated collinear magnetic materials ofer signifcant advantages for spintronic applications,including robustness against magnetic feld perturbations,no stray felds,and ultrafast dynamics.A...Two-dimensional(2D)fully compensated collinear magnetic materials ofer signifcant advantages for spintronic applications,including robustness against magnetic feld perturbations,no stray felds,and ultrafast dynamics.Among these materials,fully compensated ferrimagnets are particularly promising due to their unique characteristics such as the magneto-optical efect,completely spin-polarized currents,and the anomalous Hall efect.We performed a structural search on 2D unconventional stoichiometric Cr-I crystals using a global optimization algorithm.The most stable CrI-P21/m monolayer is a fully compensated ferrimagnetic semiconductor with a band gap of 1.57 eV and a high magnetic transition temperature of 592 K.The spontaneous spin splitting in CrI-P21/m originates from the inequivalent local coordination environments of Cr^(1)and Cr^(2)ions,yielding a mismatch in their 3d orbitals splitting.Notably,carrier doping at a concentration of 0.01 electrons or holes per atom enables reversible spin polarization,generating a fully spin-polarized current in CrI-P21/m.This performance makes it a highly promising candidate for spintronic devices.Our fndings not only provide a structural paradigm for discovering fully compensated ferrimagnets but also open a new avenue for designing zero-moment magnetic materials with intrinsic spin splitting.展开更多
Four novel chiral honeycomb structures inspired by the biological arrangement shape are designed.The functional principle is raised to solve the large deformation of bio-inspired structures and the structural constitu...Four novel chiral honeycomb structures inspired by the biological arrangement shape are designed.The functional principle is raised to solve the large deformation of bio-inspired structures and the structural constitutive model is proposed to explain the quasi-static mechanical properties of chiral honeycomb array structures and honeycomb structures.Simulation and experiment results verify the accuracy of theoretical analysis results and the errors are all within 15%.In structural mechanical properties,Equidimensional Chiral Honeycomb Array Structure(ECHS)has excellent mechanical properties.Among ECHS,Small-sized Column Chiral Honeycomb Array Structure(SCHCS)has the best properties.The bearing capacity,specific energy absorption,and specific strength of SCHCS are more than twice as much as the others in this paper.The chiral honeycomb array structure has the best mechanical properties at a certain size.In the structural design,the optimal size model should be obtained first in combination with the optimization algorithm for the protection design.展开更多
On-demand and real-time generation of arbitrary complex fields directly from the laser source holds significant appeal for myriad applications. In this Letter, we demonstrate a ring laser configuration capable of dyna...On-demand and real-time generation of arbitrary complex fields directly from the laser source holds significant appeal for myriad applications. In this Letter, we demonstrate a ring laser configuration capable of dynamically generating arbitrary transverse fields. In a ring laser resonator, two cascaded phase modulations are utilized, which permits the control of two beams with high efficiency and high fidelity. The zeroth-order beam is a fundamental Gaussian field that self-reproduces itself in the resonator. The first-order beam serves as the desired output field, which is separated from the selfreproduction mode to facilitate the on-demand manipulation of amplitude and phase. In the verification experiments,a series of typical Hermite–Gaussian(HG) modes, Laguerre–Gaussian(LG) modes, flat-top mode, and amplitude-only pattern“A” are generated from the ring laser configuration. This innovative ring laser resonator may open up new perspectives for the design of structured-light lasers, with potential impacts in applications such as particle manipulation, advanced microscopy, and next-generation optical communication.展开更多
文摘In this paper, we develop a new theoretical framework by means of the absorbing Markov process theory for analyzing some stochastic global optimization algorithms. Applying the framework to the pure random search, we prove that the pure random search converges to the global minimum in probability and its time has geometry distribution. We also analyze the pure adaptive search by this framework and turn out that the pure adaptive search converges to the global minimum in probability and its time has Poisson distribution.
基金the National Natural Science Foundation of China(Nos.51779135 and 51009087)the Natural Science Foundation of Shanghai(No.14ZR1419500)。
文摘Rankine source method,optimization technology,parametric modeling technology,and improved multiobjective optimization algorithm were combined to investigate the multiobjective optimization design of hull form.A multiobjective and multilevel optimization design framework was constructed for the comprehensive navigation performance of ships.CAESES software was utilized as the optimization platform,and nondominated sorting genetic algorithm II(NSGA-II)was used to conduct multiobjective optimization research on the resistance and sea-keeping performance of the ITTC Ship A-2 fishing vessel.Optimization objectives of this study are heave/pitch response amplitude and wave-making resistance.Taking the displacement and the length between perpendiculars as constraints,we optimized the profile of the hull.Analytic hierarchy process(AHP)and technique for order preference by similarity to ideal solution(TOPSIS)were used to sort and select Pareto solutions and determine weight coefficient of each navigation performance objective in the general objective.Finally,the hydrodynamic performance before and after the parametric deformation of the hull was compared.The results show that both the wave-making resistance and heave/pitch amplitude of the optimized hull form are reduced,and the satisfactory optimal hull form is obtained.The results of this study have a certain reference value for the initial stage of multiobjective optimization design of hull form.
基金supported by the National Natural Science Foundation of China (10832004 and 10672084).
文摘Based on the trajectory design of a mission to Saturn, this paper discusses four different trajectories in various swingby cases. We assume a single impulse to be applied in each case when the spacecraft approaches a celestial body. Some optimal trajectories ofEJS, EMS, EVEJS and EVVEJS flying sequences are obtained using five global optimization algorithms： DE, PSO, DP, the hybrid algorithm PSODE and another hybrid algorithm, DPDE. DE is proved to be supe- rior to other non-hybrid algorithms in the trajectory optimi- zation problem. The hybrid algorithm of PSO and DE can improve the optimization performance of DE, which is vali- dated by the mission to Saturn with given swingby sequences. Finally, the optimization results of four different swingby sequences are compared with those of the ACT of ESA.
文摘This paper presents a new stochastic algorithm for box constrained global optimization problem. Bacause the level set of objective function is always not known, the authors designed a region containing the current minimum point to replace it, and in order to fit the level set well, this region would be walking and contracting in the running process. Thus, the new algorithm is named as region's walk and contraction(RWC). Some numerical experiments for the RWC were conducted, which indicate good property of the algorithm.
基金the National Natural Science Foundation of China(No.11771275).
文摘In this study,we consider the global optimization problem in a hypercube.We use a class of series to construct a curve in a hypercube,which can fill the hypercube,and we present an integral function on the curve.Based on the integral function,we propose an algorithm for solving the global optimization problem.Then,we perform a convergence analysis and numerical experiments to demonstrate the effectiveness of the proposed algorithm.
文摘In this paper, the improvement of pure random search is studied. By taking some information of the function to be minimized into consideration, the authors propose two stochastic global optimization algorithms. Some numerical experiments for the new stochastic global optimization algorithms are presented for a class of test problems.
基金supported by the Natural Science Foundation of Wenzhou Institute,University of Chinese Academy of Sciences(UCAS)(Grant No.WIUCASQD2023004)the National Natural Science Foundation of China(Grant Nos.12304006,12404265,and 12435001)+2 种基金the Natural Science Foundation of Shanghai,China(Grant No.23JC1401400)the Natural Science Foundation of Wenzhou(Grant No.L2023005)the Fundamental Research Funds for the Central Universities of East China University of Science and Technology。
文摘Two-dimensional(2D)fully compensated collinear magnetic materials ofer signifcant advantages for spintronic applications,including robustness against magnetic feld perturbations,no stray felds,and ultrafast dynamics.Among these materials,fully compensated ferrimagnets are particularly promising due to their unique characteristics such as the magneto-optical efect,completely spin-polarized currents,and the anomalous Hall efect.We performed a structural search on 2D unconventional stoichiometric Cr-I crystals using a global optimization algorithm.The most stable CrI-P21/m monolayer is a fully compensated ferrimagnetic semiconductor with a band gap of 1.57 eV and a high magnetic transition temperature of 592 K.The spontaneous spin splitting in CrI-P21/m originates from the inequivalent local coordination environments of Cr^(1)and Cr^(2)ions,yielding a mismatch in their 3d orbitals splitting.Notably,carrier doping at a concentration of 0.01 electrons or holes per atom enables reversible spin polarization,generating a fully spin-polarized current in CrI-P21/m.This performance makes it a highly promising candidate for spintronic devices.Our fndings not only provide a structural paradigm for discovering fully compensated ferrimagnets but also open a new avenue for designing zero-moment magnetic materials with intrinsic spin splitting.
基金This work is supported by National Key R&D program of of China(No.2022YFB4600500)the National Natural Science Foundation of China(No.51975246)+2 种基金the Science and Technology Development Program of Jilin Province,China(No.20220101192JC)Capital construction fund plan within the budget of Jilin Province(No.2023C041-4)Chongqing Natural Science Foundation(No.CSSTB2022NSCQ-MSX0225).
文摘Four novel chiral honeycomb structures inspired by the biological arrangement shape are designed.The functional principle is raised to solve the large deformation of bio-inspired structures and the structural constitutive model is proposed to explain the quasi-static mechanical properties of chiral honeycomb array structures and honeycomb structures.Simulation and experiment results verify the accuracy of theoretical analysis results and the errors are all within 15%.In structural mechanical properties,Equidimensional Chiral Honeycomb Array Structure(ECHS)has excellent mechanical properties.Among ECHS,Small-sized Column Chiral Honeycomb Array Structure(SCHCS)has the best properties.The bearing capacity,specific energy absorption,and specific strength of SCHCS are more than twice as much as the others in this paper.The chiral honeycomb array structure has the best mechanical properties at a certain size.In the structural design,the optimal size model should be obtained first in combination with the optimization algorithm for the protection design.
基金supported by the National Key R&D Program of China (No.2023YFB3610701)the Hubei Provincial Central-Guided Local Science and Technology Development Special Program (2023CGB001)+3 种基金the Hubei Provincial Key Research and Development Program (No.2022BAA009)the Major Science and Technology Special Project of Hubei Province (No.2021AAA009)the Wuhan Science and Technology Project (No.20210120020234244)the Major Program (JD) of Hubei Province (No.2023BAA015)。
文摘On-demand and real-time generation of arbitrary complex fields directly from the laser source holds significant appeal for myriad applications. In this Letter, we demonstrate a ring laser configuration capable of dynamically generating arbitrary transverse fields. In a ring laser resonator, two cascaded phase modulations are utilized, which permits the control of two beams with high efficiency and high fidelity. The zeroth-order beam is a fundamental Gaussian field that self-reproduces itself in the resonator. The first-order beam serves as the desired output field, which is separated from the selfreproduction mode to facilitate the on-demand manipulation of amplitude and phase. In the verification experiments,a series of typical Hermite–Gaussian(HG) modes, Laguerre–Gaussian(LG) modes, flat-top mode, and amplitude-only pattern“A” are generated from the ring laser configuration. This innovative ring laser resonator may open up new perspectives for the design of structured-light lasers, with potential impacts in applications such as particle manipulation, advanced microscopy, and next-generation optical communication.
