共查询到10条相似文献,搜索用时 140 毫秒
1.
Community detection is believed to be a very important tool for understanding both the structure and function of complex networks, and has been intensively investigated in recent years. Community detection can be considered as a multi-objective optimization problem and the nature-inspired optimization techniques have shown promising results in dealing with this problem. In this study, we present a novel multi-objective discrete backtracking search optimization algorithm with decomposition for community detection in complex networks. First, we present a discrete variant of the backtracking search optimization algorithm (DBSA) where the updating rules of individuals are redesigned based on the network topology. Then, a novel multi-objective discrete method (MODBSA/D) based on the proposed discrete variant DBSA is first proposed to minimize two objective functions in terms of Negative Ratio Association (NRA) and Ratio Cut (RC) of community detection problems. Finally, the proposed algorithm is tested on some real-world networks to evaluate its performance. The results clearly show that MODBSA/D has effective and promising performance for dealing with community detection in complex networks. 相似文献
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Reliability-based structural optimization of frame structures for multiple failure criteria using topology optimization techniques 总被引:1,自引:2,他引:1
Katsuya Mogami Shinji Nishiwaki Kazuhiro Izui Masataka Yoshimura Nozomu Kogiso 《Structural and Multidisciplinary Optimization》2006,32(4):299-311
Topology optimization methods using discrete elements such as frame elements can provide useful insights into the underlying mechanics principles of products; however, the majority of such optimizations are performed under deterministic conditions. To avoid performance reductions due to later-stage environmental changes, variations of several design parameters are considered during the topology optimization. This paper concerns a reliability-based topology optimization method for frame structures that considers uncertainties in applied loads and nonstructural mass at the early conceptual design stage. The effects that multiple criteria, namely, stiffness and eigenfrequency, have upon system reliability are evaluated by regarding them as a series system, where mode reliabilities can be evaluated using first-order reliability methods. Through numerical calculations, reliability-based topology designs of typical two- or three-dimensional frames are obtained. The importance of considering uncertainties is then demonstrated by comparing the results obtained by the proposed method with deterministic optimal designs. 相似文献
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This paper describes the multiobjective topology optimization of continuum structures solved as a discrete optimization problem
using a multiobjective genetic algorithm (GA) with proficient constraint handling. Crucial to the effectiveness of the methodology
is the use of a morphological geometry representation that defines valid structural geometries that are inherently free from
checkerboard patterns, disconnected segments, or poor connectivity. A graph- theoretic chromosome encoding, together with
compatible reproduction operators, helps facilitate the transmission of topological/shape characteristics across generations
in the evolutionary process. A multicriterion target-matching problem developed here is a novel test problem, where a predefined
target geometry is the known optimum solution, and the good results obtained in solving this problem provide a convincing
demonstration and a quantitative measure of how close to the true optimum the solutions achieved by GA methods can be. The
methodology is then used to successfully design a path-generating compliant mechanism by solving a multicriterion structural
topology optimization problem. 相似文献
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微型柔性机构的多目标计算机辅助拓扑优化设计 总被引:5,自引:0,他引:5
提出了基于结构整体柔度最小化和结构输出位移最大化的多目标拓扑优化设计方法,建立了微型柔性机构的多目标拓扑优化设计模型.提出了适用于微型柔性机构多目标拓扑优化设计的伴随矩阵敏度分析方法,并将广义收敛移动渐进算法用于多目标多约束微型柔性机构拓扑优化问题的求解.最后通过数值计算验证了优化模型的有效性. 相似文献
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Topology optimization has become very popular in industrial applications, and most FEM codes have implemented certain capabilities of topology optimization. However, most codes do not allow simultaneous treatment of sizing and shape optimization during the topology optimization phase. This poses a limitation on the design space and therefore prevents finding possible better designs since the interaction of sizing and shape variables with topology modification is excluded. In this paper, an integrated approach is developed to provide the user with the freedom of combining sizing, shape, and topology optimization in a single process. 相似文献
8.
粒子群算法(PSO)的拓扑结构是影响算法性能的关键因素,为了从根源上避免粒子群算法易陷入局部极值及早熟收敛等问题,提出一种混合拓扑结构的粒子群优化算法(MPSO)并将其应用于软件结构测试数据的自动生成中。通过不同邻域拓扑结构对算法性能影响的分析,采用一种全局寻优和局部寻优相结合的混合粒子群优化算法。通过观察粒子群的多样性反馈信息,对每一代种群粒子以进化时选择全局拓扑结构模型(GPSO)或局部拓扑结构模型(LPSO)的方法进行。实验结果表明,MPSO使得种群的多样性得到保证,避免了粒子群陷入局部极值,提高了算法的收敛速度。 相似文献
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Discrete optimization of truss structures is a hard computing problem with many local minima. Metaheuristic algorithms are naturally suited for discrete optimization problems as they do not require gradient information. A recently developed method called Jaya algorithm (JA) has proven itself very efficient in continuous engineering problems. Remarkably, JA has a very simple formulation and does not utilize algorithm-specific parameters. This study presents a novel JA formulation for discrete optimization of truss structures under stress and displacement constraints. The new algorithm, denoted as discrete advanced JA (DAJA), implements efficient search mechanisms for generating new trial designs including discrete sizing, layout and topology optimization variables. Besides the JA’s basic concept of moving towards the best design of the population and moving away from the worst design, DAJA tries to form a set of descent directions in the neighborhood of each candidate designs thus generating high quality trial designs that are very likely to improve current population. Results collected in seven benchmark problems clearly demonstrate the superiority of DAJA over other state-of-the-art metaheuristic algorithms and multi-stage continuous–discrete optimization formulations. 相似文献
10.
Topology optimization with design-dependent pressure loading 总被引:1,自引:1,他引:0
Bin Zheng Ching-jui Chang Hae Chang Gea 《Structural and Multidisciplinary Optimization》2009,38(6):535-543
In this paper, the layout of structures under design-dependent pressure loading is optimized using a topology optimization
approach. In contrast to topology optimization problems with conventional static external loading, the position and direction
of pressure loading are changing with topology of structure during optimization iterations. In order to model the changing
structural surface boundaries under design-dependent pressure loading, a pseudo equal-potential function is introduced. Design
sensitivity analysis is derived from the adjoint method. Three examples solved by the proposed method are presented. 相似文献