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  • Open Access

    ARTICLE

    An Intelligent Algorithm for Solving Weapon-Target Assignment Problem: DDPG-DNPE Algorithm

    Tengda Li, Gang Wang, Qiang Fu*, Xiangke Guo, Minrui Zhao, Xiangyu Liu

    CMC-Computers, Materials & Continua, Vol.76, No.3, pp. 3499-3522, 2023, DOI:10.32604/cmc.2023.041253

    Abstract Aiming at the problems of traditional dynamic weapon-target assignment algorithms in command decision-making, such as large computational amount, slow solution speed, and low calculation accuracy, combined with deep reinforcement learning theory, an improved Deep Deterministic Policy Gradient algorithm with dual noise and prioritized experience replay is proposed, which uses a double noise mechanism to expand the search range of the action, and introduces a priority experience playback mechanism to effectively achieve data utilization. Finally, the algorithm is simulated and validated on the ground-to-air countermeasures digital battlefield. The results of the experiment show that, under the framework of the deep neural… More >

  • Open Access

    ARTICLE

    Rien ne sert de courir, il faut partir à point ; Leçons apprises d’une intervention psychologique en oncologie : de l’importance de conduire des études pilotes et/ou de faisabilité dans les interventions complexes

    Sophie Lelorain1,*, Christelle Duprez2, Laura Caton2, Marie-Mai Nguyen2, Gildas d’Almeida2, Guillaume Piessen3, Alexis Cortot4

    Psycho-Oncologie, Vol.17, No.3, pp. 201-209, 2023, DOI:10.32604/po.2023.044910

    Abstract Cet article retrace l’histoire d’un projet de recherche qui a échoué. Nous avons conçu et implémenté une intervention psychologique visant à augmenter les compétences émotionnelles des patient·e·s atteint·e·s de cancer œsogastrique ou de cancer du poumon, après leurs traitements. L’étude était un essai contrôlé randomisé dans un hôpital public. Nous présentons le protocole final de l’étude, décrivons les difficultés rencontrées et nos réflexions à ce sujet, afin de transmettre notre expérience et les messages clefs qui vont avec aux chercheur·e·s et clinicien·ne·s pour la mise en œuvre de telles interventions. Tout d’abord, le rôle de la psychologie, des émotions et… More >

  • Open Access

    PROCEEDINGS

    Design Sensitivity Analysis of Thin-Body Acoustic Problems Above an Infinite Impedance Plane by Using a Fast Multipole Indirect BEM

    Menghui Liang1, Changjun Zheng1,*, Yongbin Zhang1, Chuanxing Bi1

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09605

    Abstract This paper presents an accurate and efficient indirect boundary element method (IBEM) accelerated by the fast multipole algorithm (FMA)for the design sensitivity analysis of large-scale thin-body acoustic problems above an infinite impedance plane. The non-uniqueness issue of the IBEM in solving exterior acoustic problems is avoided by applying a hybrid combination of single- and double-layer potentials. The half-space impedance Green’s function which involves an image complex line source and is valid for both mass-like and spring-like impedance plane is employed to involve the sound-absorbing effect of the ground surface. Explicit evaluation formulations of the singular boundary integrals are derived and… More >

  • Open Access

    PROCEEDINGS

    A Fast Direct Boundary Element Method for 3D Acoustic Problems Based on Hierarchical Matrices

    Ruoyan Li1,2, Yijun Liu1,*, Wenjing Ye2

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09472

    Abstract The boundary element method (BEM) for acoustic problems is a numerical method based on solving the discretized boundary integral equation (BIE) corresponding to the Helmholtz equation. A fast direct BEM for 3D acoustic problems is proposed in this paper, which is more suitable for broadband acoustic simulation of complex structures, such as in the design and analysis of acoustic metamaterials. The main idea of the fast direct solver is based on the hierarchical off-diagonal low-rank (HODLR) matrix, randomized interpolative decomposition and fast matrix inversion formula. Several numerical examples in solving both interior and exterior acoustic problems are presented in this… More >

  • Open Access

    PROCEEDINGS

    Structural Damage Identification Using Modal Energy and Improved Hybrid Gradient-Based Optimizer

    Nizar Faisal Alkayem1, Maosen Cao2,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09367

    Abstract Structural damage identification is a key engineering technique that attempts to ensure structural reliability. In this regard, one of the major intelligent approaches is the inverse analysis of structural damage using metaheuristics. By considering the recent achievements, an efficient hybrid objective function that combines the modal kinetic energy and modal strain energy is developed. The objective function aims to extract maximum modal information from the structure and overcome noisy conditions. Moreover, the original methods are usually vulnerable to the associated high multimodality and uncertainty of the inverse problem. Therefore, the particle swarm algorithm (PSO) mechanism is combined with another newly… More >

  • Open Access

    PROCEEDINGS

    A Multi-Frequency Topology Optimization Method for Vibro-Acoustic Problems

    Dan Li1, Jie Wang1, Haibo Chen1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-2, 2023, DOI:10.32604/icces.2023.09139

    Abstract In practical vibro-acoustic problems, the external excitation normally contains a certain frequency band structure [1]. Therefore, it is needed to perform optimization under frequency band analysis. For sound radiation problems caused by structural vibration, a topology optimization method for structural materials is proposed based on the acoustic-vibration coupling analysis [2-6] and the frequency-band matrix interpolation method [7,8]. By combining the advantages of FEM and BEM in structural and acoustic field analysis, the accurate solution of the acoustic-vibration coupling problem is achieved. The structural material interpolation model is established using the solid isotropic material with penalization (SIMP) method, and the topological… More >

  • Open Access

    PROCEEDINGS

    Collocation-Based Reconstruction Harmonic Balance Method for Solving Periodic Orbits of Aerospace Vehicles

    Zipu Yan1,2, Honghua Dai1,2,*, Xiaokui Yue1,2

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.09138

    Abstract As a significant research interest in orbital mechanics, periodic orbits are fundamental for understanding orbital behaviors and space explorations. Although the harmonic balance (HB) method and its variants have been the most widely-used approaches for periodic dynamical systems, they are seldom applied to celestial dynamics. Here we use the reconstruction harmonic balance (RHB) method for solving periodic orbits. Starting from a presupposed Fourier form and an initial guess at the solution, the algorithm uses timedomain collocation points to optimally reconstruct the high-order HB procedure without complicated symbolic operations and non-physical solutions. Following a description of the method, it is applied… More >

  • Open Access

    PROCEEDINGS

    An Efficient Solution Strategy for Phase Field Model of Dynamic Fracture Problems Based on Domain Decomposition

    Shourong Hao1, Yongxing Shen1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09336

    Abstract Dynamic fracture is an important class of damage widely present in engineering materials and structures, e.g., high-speed impact and explosion. In recent years, the phase field approach to fracture proposed by Bourdin et al. [1] becomes popular for complicated fracture problems for its ability to simulate crack nucleation, propagation, branching, and merging without extra criteria, and the crack path does not need to be tracked, which makes the implementation straightforward and the calculation efficient. However, one of the major issues of the phase field method is the high computational cost due to the need of a very fine mesh, which… More >

  • Open Access

    PROCEEDINGS

    Verification of Contact Algorithm for Impact Problems with Numerical Manifold Method

    Qiumeng Ouyang1, Ge Kang1,*, Pengwan Chen1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010514

    Abstract Impact phenomenon is a complicated mechanical problems frequently encountered in our daily life, especially in the military field. Numerical manifold method (NMM) is a novel numerical theory which is proposed based on dual-topology to solve the continuous-discontinues displacement field in both static and dynamic mechanical problems. In the present work, the 3D-NMM program framework enriched with the cover-based contact theory is developed to simulate the impact mechanical problems. Classic Taylor rod experiments with different length-diameter ratios and hitting velocities (150-250m/s) are systematic conducted with ourselves code. The simulation shows that as the impact speed increasing, the plastic deformation of the… More >

  • Open Access

    PROCEEDINGS

    MPI Massive Parallelization of Smoothed Particle Hydrodynamics for Simulation of Impact and Explosion Problems

    Jiahao Liu1, Moubin Liu1,*

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010056

    Abstract The dynamic failure process of structures under impact and explosive loading is very common in both military and industrial fields. However, the conventional mesh-based method has some shortcomings, such as large mesh distortion and sliding surface treatment. Some typical phenomena are difficult to be simulated. The smoothed particle hydrodynamics (SPH) method has natural advantages in treating large material deformations in impact and explosion problems [1]. To make the SPH method suitable for the impact and explosion problems, it is also improved by some treatments [2] to avoid inherent stress instability and unphysical oscillation. However, numerical calculations for 3D engineering applications,… More >

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