基于改进模拟退火算法的无线传感器布设

对于已被证明是组合优化问题的无线传感器布设而言,模拟退火算法是一种有效的解决方法.在生成无线传感器布设方案的过程中,针对传统模拟退火算法的缺陷,采用了保存当前最优布设方案及灵活设置退火温度的改进算法来生成布设方案,并给出了使用该算法的无线传感器布设方案生成流程及算法伪码.最后通过仿真实验验证了该改进算法在生成无线传感器...     

A parallel simulated annealing algorithm based on functional feature tree modeling for 3D engineering layout design

Computation complexity and modeling complexity are primary clog in 3D engineering layout design. In this paper, a parallel simulated annealing based on multiple Markov chains is employed to deal with the computation complexity. The algorithm increases computing efficiency by allocating computation burden to networked computers. To cope with the modeling complexity, machine components and space limitation are modeled by a hierarchical, feature-based modeling method—the functional feature tree modeling method. And multiple complex design constraints can be described by the representation. In order to support whole layout design solving process, a Computer Aided Layout Design System is introduced briefly. This system not only implements the algorithm and the components representation, but also integrates some other subsystems as evaluation system, constrains editor etc. The methods are demonstrated through a real engineering application, a vehicle engine compartment layout design.     

Two-dimensional equilibrium constraint layout using simulated annealing

This paper studies the layout optimization problem with equilibrium constraint. It is a two-dimensional packing problem with the industrial background of simplified satellite module layout design, and is known as NP-hard problem. By incorporating the heuristic neighborhood search mechanism and the adaptive gradient method into the simulated annealing procedure, a heuristic simulated annealing algorithm is put forward for this problem. The special neighborhood search mechanism can avoid the disadvantage of blind search in the simulated annealing algorithm, and the adaptive gradient method is used to execute local search and speed up finding the global optimal solution. Numerical examples are illustrated to verify the effectiveness of the proposed algorithm.     

Two-dimensional equilibrium constraint layout using simulated annealing

This paper studies the layout optimization problem with equilibrium constraint. It is a two-dimensional packing problem with the industrial background of simplified satellite module layout design, and is known as NP-hard problem. By incorporating the heuristic neighborhood search mechanism and the adaptive gradient method into the simulated annealing procedure, a heuristic simulated annealing algorithm is put forward for this problem. The special neighborhood search mechanism can avoid the disadvantage of blind search in the simulated annealing algorithm, and the adaptive gradient method is used to execute local search and speed up finding the global optimal solution. Numerical examples are illustrated to verify the effectiveness of the proposed algorithm.     

用非常快速模拟重复退火算法实现的模拟电路模块布局

提出了基于非常快速模拟重复退火算法实现模拟电路模块布局的方法,该算法指数倍地快于传统的Cauchy 或 Bolzmann退火算法.其中使用一个滑行函数将绝对布局问题转化为相对布局问题,这样极大地减少了算法的搜索空间,而不会降低搜索成功率.价值函数根据模拟集成电路固有的特点设计而成,模拟电路设计者可根据电路的具体要求选择合适的网络长度估算器.使用最小steiner树方法的全局布线器与布局器同时工作,减轻了后续细节布线环节的工作量,并保证最后布局结果的可用性.最后,给出了使用该布局方法实现运算放大器的版图事例.     

Tabu Search Heuristic for Point-Feature Cartographic Label Placement

The generation of better label placement configurations in maps is a problem that comes up in automated cartographic production. The objective of a good label placement is to display the geographic position of the features with their corresponding label in a clear and harmonious fashion, following accepted cartographic conventions. In this work, we have approached this problem from a combinatorial optimization point of view, and our research consisted of the evaluation of the tabu search (TS) heuristic applied to cartographic label placement. When compared, in real and random test cases, with techniques such as simulated annealing and genetic algorithm (GA), TS has proven to be an efficient choice, with the best performance in quality. We concluded that TS is a recommended method to solve cartographic label placement problem of point features, due to its simplicity, practicality, efficiency and good performance along with its ability to generate quality solutions in acceptable computational time.     

Solving optimization problems by parallel recombinative simulatedannealing on a parallel computer-an application to standard cellplacement in VLSI design

In this paper, parallel recombinative simulated annealing (PRSA), a hybrid method with features of simulated annealing and genetic algorithms, is examined. PRSA inherits the global convergence property from simulated annealing and the parallelism property from genetic algorithms. PRSA was implemented on a monoprocessor system as well as on a transputer. The algorithm, its parallel implementation, and its application to an NP-hard problem, namely standard cell placement in very large scale integration (VLSI) chip design, are described. PRSA was run for a large range of test cases. Since its performance depends on many parameters, the effects of parameter variations are studied in detail. Some important parameters are migration of individuals to other transputer nodes and selection strategies for constructing new populations. In comparison with simulated annealing and genetic algorithms, PRSA was found to produce better solutions.     

基于混合遗传模拟退火算法的SaaS构件优化放置

目前,对于SaaS优化放置问题的研究都是假定云环境中的虚拟机的种类和数量都是确定的,即,在限定的资源范围内进行优化.然而,在公有云环境下,SaaS提供者所需要的云资源数量是不确定的,其需要根据Iaa S提供者所提供的虚拟机种类以及被部署的SaaS构件的资源需求来确定.为此,站在SaaS提供者角度,提出一种新的SaaS构件优化放置问题模型,并采用混合遗传模拟退火算法(hybrid genetic and simulated annealing algorithm,简称HGSA)对该问题进行求解.HGSA结合了遗传算法和模拟退火算法的优点,克服了遗传算法收敛速度慢和模拟退火算法容易陷入局部最优的缺点,与单独使用遗传算法和模拟退火算法相比,实验结果表明,HGSA在求解SaaS构件优化放置问题方面具有更高的求解质量.所提出的方法为SaaS服务模式的大规模应用提供了理论与方法的支撑.     

生产车间设备布局线性模型及算法研究

文章分析了线性布局形式的多样性,提出了虚拟环境下生产车间设备布局的线性模型,研究了模拟退火算法的特点,并运用模拟退火算法及其改进算法求解该线性模型,最后给出了一个实例。     

EDA软件中的布局优化算法分析及其改进

在深亚微米、超深亚微米工艺水平下的超大规模集成电路设计需要高性能的EDA(电子设计自动化,ElectricalDesignAutomation)软件的支持。与物理设计相关的布图设计中,布局设计是一个极为重要的环节。该文以FPGA(现场可编程门电路,FieldProgrammableGateArray)为例,分析和介绍了EDA中的布局算法,然后利用遗传模拟退火算法对原算法提出了改进,并在文章中介绍了改进后的算法。     

Efficiency analysis for stochastic dynamic facility layout problem using meta-heuristic,data envelopment analysis and machine learning

The facility layout problem (FLP) is a combinatorial optimization problem. The performance of the layout design is significantly impacted by diverse, multiple factors. The use of algorithmic or procedural design methodology in ranking and identification of efficient layout is ineffective. In this context, this study proposes a three-stage methodology where data envelopment analysis (DEA) is augmented with unsupervised and supervised machine learning (ML). In stage 1, unsupervised ML is used for the clustering of the criteria in which the layouts need to be evaluated using homogeneity. Layouts are generated using simulated annealing, chaotic simulated annealing, and hybrid firefly algorithm/chaotic simulated annealing meta-heuristics. In stage 2, the nonparametric DEA approach is used to identify efficient and inefficient layouts. Finally, supervised ML utilizes the performance frontiers from DEA (efficiency scores) to generate a trained model for getting the unique rankings and predicted efficiency scores of layouts. The proposed methodology overcomes the limitations associated with large datasets that contain many inputs / outputs from the conventional DEA and improves the prediction accuracy of layouts. A Gaussian distribution product demand dataset for time period T = 5 and facility size N = 12 is used to prove the effectiveness of the methodology.     

Solution of the facilities layout problem by simulated annealing

The simulated annealing method (SAM) is a radically new and powerful approach to solving certain integer optimization problems. The paper describes its application to the facility layout problem (QAP) and shows how it can generally match or produce superior solutions to the best known values for classical benchmark problems. The technique is also suited to microcomputer solution using interactive graphics for practical layout problems.     

A hybrid optimization approach for layout design of unequal-area facilities

A hybrid optimization approach is presented for the layout design of unequal-area facilities. Simulated annealing is used to optimize a randomly generated initial placement on an “extended plane” considering the unequal-area facilities enclosed in magnified envelop blocks. An analytical method is then applied to obtain the optimum placement of each envelop block in the direction of steepest descent. Stepwise reduction of the sizes of the envelop blocks allows controlled convergence in a multi-phase optimization process. The presented test problems include two large size benchmark problems of 50 and 100 facilities of unequal areas. The results indicate that although the computational cost is relatively quite high, the technique is a significant improvement over previously published techniques for unequal-area facilities and can yield solutions of the same quality as obtained by PLANOPT, a general-purpose layout optimization program based on pseudo-exhaustive search.     

Model layout optimization for solid ground curing rapid prototyping processes

Rapid prototyping technologies are capable of directly manufacturing physical objects from CAD models and have been increasingly used in product development, tool and die making and fabrication of functional parts. Solid ground curing (SGC) technology, one of the rapid prototyping technologies, is suitable of building multiple parts with different geometry and dimensions in batch production of rapid prototypes to minimize the cost of prototypes. However, the layout of CAD models in a graphic environment is time-consuming. Because of high cost of the resin, the layout of models in a batch is critical for the success of the SGC operations in any industrial environment. This paper presents the layout optimization using simulated annealing techniques. A software system was developed to assist Cubital operators to layout CAD models with various geometric shapes. The system accepts STL files from any solid modeling environment. Several examples are provided to illustrate the techniques and effectiveness of the approach.     

岛式FPGA线长驱动快速布局算法

传统的FPGA布局箅法需要花费大量时间,影响了FPGA物理设计效率.为了在保证布局质量的前提下缩短布局时间,提出一种岛式FPGA快速布局算法.首先考虑终端传输的迭代二划分,然后进行最小费用流初始布局和低温模拟退火的布局优化.在每一个划分层次中,考虑了线网的终端对线网权重的影响;对于每一个划分的区域,使用最小费用流来确定初始的布局;在布局的最后阶段使用低温模拟退火来提高初始布局的质量.实验结果表明,该算法布局结果的质量高、速度快.     

BBL布局的均场退火方法

均场退火方法既可以看作是一种新的神经网络计算模型,又可视为是对模拟退火的重大改进,提出了一个基于均场退火方法的任意单元布局算法,用一个三维二值换位矩阵将问题映射了为神经网络,建立包含重叠约束和优化目标的能量函数,再用均场退火方程迭代求解,每个单元只能放置在布局平面一个位置上的约束,用神经元归一化的方法解决。     

可配置宏的快速FPGA布局算法

提出一种可配置宏模块的快速FPGA布局算法。用解析模型确定所有宏模块及基本逻辑模块的理想位置,通过局部扩散得到一个合理的初始布局方案,用低温模拟退火进一步优化,确定各模块的最终位置。以平方线网总长度为目标函数,与VPR算法相比,该算法能较好地处理宏模块,大大降低布局所耗费的时间,不影响最终布局方案的质量。     

Progressive sharing of modules among product variants

Recent market transition from mass production to mass customization forces manufacturers to design products that meet individual requirements. In order to address the high cost of this practice, manufacturers develop product families with a common platform, whose variants are designed to meet different customer demands. Parallel to this transition, the dynamics of the market forces designers to develop products composed of modules that are standardized as much as possible across products, thus can be more resilient than complete designs in a changing world.Starting from an original set of different components, our method designs a modular common platform and additional modules, shared by subsets of the designs, from which variants are composed.We applied the method to the layout design of a set of products. Consequently, the geometric aspect of the product family optimization is emphasized, but functional aspects related to the product features and to customer needs are also addressed due to their manifestation in the layout. The design search space is explored using shape grammar rules that alter component geometry and therefore, functionality. The search for optimal design is performed using simulated annealing. Given different objective formulations or parameter settings, the method can be used to explore the solution space. A simple example problem demonstrates the feasibility of the method.     

An efficient two-staged approach for generating block layouts

Multidimensional scaling (MDS) is a useful mathematical tool that enables the analysis of data in areas where organized concepts and underlying dimensions are not well developed. In this paper, MDS algorithms are used as a dimension reduction tool which arranges facilities in a two-dimensional space while preserving the adjacency relationship between facilities. The output of MDS is a scatter diagram and is in turn used as the input or location references for developing into the final block layout. The bay structures of layout are considered where the given floor space is first partitioned horizontally or vertically into bays, which are subsequently partitioned into the blocks. Rotating the scatter diagram about the origin results in different layouts in the bay structure. A simulated annealing approach is adopted to rotate the scatter diagram so that the total cost of traveling between facilities and shape violation in the final layout is minimized.Scope and purposeThis paper discusses the application of multidimensional scaling (MDS) and simulated annealing (SA) to efficiently design facility layout. MDS is a powerful mathematical tool widely used in psychometry as well as in marketing research. By using MDS to generate a reference scatter diagram, a layout can subsequently be developed. The SA algorithm is then applied to rotate the scatter diagram from MDS so that a layout with the total cost of traveling between facilities being minimized can be obtained.