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1.
针对信誉系统中的传递模式信誉值计算算法,分析了该算法在归一化、通过相对值计算全局信誉值(GRV)以及评价函数标准不同时引起的信息损失问题和节点可信度不确定性带来的问题,基于可信度方法对该算法进行了改进。仿真实验结果表明,改进后的算法计算所得到的GRV序列比理想值的欧氏距离更小,提高了恶意节点识别能力。  相似文献   

2.
基于改进Criminisi算法的图像修复   总被引:4,自引:0,他引:4  
针对Criminisi算法难以获得理想的修复效果,且存在修复时间过长等缺陷,提出一种改进Criminisi算法的图像修复算法。改进优先权计算方式找到最优待修复块,完善最优匹配块搜索策略,找到最优匹配块,采用新的置信值更新方式以获得更为理想修复效果,通过仿真实验测试算法性能,结果表明,相较于Criminisi算法,改进Criminisi算法不仅获得了较理想的图像修复效果,而且大幅度减少了修复时间,提高了图像修复的效果。  相似文献   

3.
四摄像头触摸屏技术已经开始应用,但存在镜头畸变造成的定位误差和在靠近摄像头近端成像不理想的问题。对原四摄像头触摸屏在光学结构和定位计算方面进行改进。光学结构处对触摸模组的视野和照明进行分层处理,解决近端拍照效果的不理想。在定位算法方面采用基于刻度的校正算法。提出的光学结构方面和定位算法方面的改进能够提高触摸屏的定位精度和改进边角定位难度。  相似文献   

4.
王雪梅 《计算机仿真》2012,29(2):237-240
研究图像融合精度问题,由于光学传感器的光谱分辨率不同,在图像融合中易丢失信息,影响图像质量。传统的图像融合算法计算量大、实时性差的缺点,同时没有细致考虑低频分量融合规则以及高频分量邻域特征对融合的影响,因而得到的融合效果不理想。为了解决上述问题,提出了一种改进的提升小波变换图像融合新算法,算法引进了图像对称概念策略,仿真结果表明,改进的图像融合算法计算量明显减少,实时性也明显提高,与传统的标准小波变换图像融合算法以及拉普拉斯金字塔融合算法相比,较有效地提高了图像融合的精确度。  相似文献   

5.
谭鹤毅 《测控技术》2017,36(6):109-111
针对分布式多核节点系统的负载均衡难以取得最优解的问题,提出了一种基于改进极值优化的负载均衡方法.该方法通过节点的CPU占用率发现负载不均衡情况,然后用一个衡量模型估计计算与通信开销使改进的极值优化方法能够实现集群的负载均衡.仿真与实验结果表明该算法能够提高分布式集群的计算效率,是一种理想的负载均衡算法.  相似文献   

6.
随着迭代计算过程的推进,标准粒子群算法后期容易出现收敛速度较慢、精度较低、早熟及开发探索能力较弱等问题.针对上述不足,文中提出引入改进鸽群搜索算子的粒子群优化算法,采用Beta反向学习策略进行种群的初始化,实现种群粒子分布的多样性.首先采用线性和非线性变异策略改进鸽群算法中的地图罗盘算子,提高鸽群算法的开发和探索能力.然后采用改进后的组合优化鸽群算子更新粒子群中粒子位置和速度,提高收敛速度和计算精度,避免算法陷入局部最优.实验表明,文中算法提高收敛计算速度,精度达到函数设定的理想值.  相似文献   

7.
基于评分预测的协同过滤推荐算法   总被引:1,自引:1,他引:0  
传统的基于评分预测的协同过滤算法在计算用户之间相似性时只针对用户共同评过分的物品计算评分差异,然而由于不同用户共同评分的物品数目不同,使得计算标准不统一,从而导致推荐质量不理想。本文在传统算法的基础上进行改进,新算法在计算相似性的时候一方面考虑了用户共同评分的物品数,另一方面还考虑了物品的热门程度对用户相似性计算的影响。实验结果表明,新算法在推荐准确率和召回率上都比传统算法提高了1倍以上。研究还发现在算法中使用Pearson相关系 数明显好于使用欧氏距离作相似性度量标准得到的推荐效果。  相似文献   

8.
提出随机装卸工问题并将其转化为确定性问题,给出了其求解策略。针对粒子群算法简便实用但易过早收敛的问题,提出了一种结合人工免疫算法的新型混合粒子群算法,将该算法运用于求解随机装卸工问题。数值算例的计算结果表明:与基本粒子群算法相比,改进的粒子群算法在求解随机装卸工问题上表现出的求解精度和速度都十分理想。  相似文献   

9.
现有的求解网络最大流算法,存在由于增广链选取的顺序不当而无法得到理想的最大流,且在计算过程中每步都需要画一个网络图等问题.针对上述问题展开讨论,并对一些最大流算法进行改进.利用分层网络及容差的概念,在选择增广链的时候优先选择路径最短且容差较大的路径,并将已饱和的弧画上终止符.最后通过具体的算例验证了改进算法可以简单快速地找到增广链,且避免了标号过程,只需要在一个图上即可完成.整个运算过程,直观性强,计算方便.改进的算法较其他的算法具有高效性和实用性的优势.  相似文献   

10.
基于改进MC算法的医学图像三维重建研究   总被引:1,自引:0,他引:1  
MC算法是经典的三维重建方法。但它重建时效率低,产生了大量的三角面片,增加了绘制的时间和空间。而且存在拓扑二义性,会使重建后的图像产生空洞的结构,重建的效果也不是很理想。对此,提出相应的改进策略。介绍了如何提高计算效率、减少三角面片数量、消除二义性和平滑图像等方面。通过实验证明了改进算法的可行性。  相似文献   

11.
Economic equilibrium computation has raised the issue of global optimization algorithms since economic equilibrium problems can be cast as a global optimization problem. However, nearly all conventional algorithms stop when they find a local optimum. Over the last decade a number of new optimization algorithms have appeared, simulated annealing is one of them. It is a powerful stochastic search algorithm applicable to a wide range of problems for which little prior knowledge is available, and it asymptotically probabilistically converges to a global optimum. In this paper, we will give a brief introduction to simulated annealing and apply it to the computation of economic equilibrium. We also reported our computational experience in the paper. This early result shows that the application of simulated annealing to computation of economic equilibrium is encouraging and it deserves further research.  相似文献   

12.
In this paper we study new computational methods to find equilibria in generalequilibrium models. We first survey the algorithms to compute equilibria thatcan be found in the literature on computational economics and we indicate howthese algorithms can be improved from the computational point of view. We alsoprovide alternative algorithms that are able to compute the equilibria in anefficient manner even for large-scale models, based on interior-point methods.We illustrate the proposed methods with some examples taken from theliterature on general equilibrium models.  相似文献   

13.
致力于解决多智能体系统中的任务分配问题,基于社会生活中的竞争现象提出了一种多智能体竞争模型,同时提出了解决多智能体任务分配的详细算法.文章引入博弈论来研究存在相互外部约束条件下的个体选择问题.为了克服求解纳什均衡点的复杂性,本文采用了一步纳什均衡的方法.仿真结果证明了本模型的合理性和算法的有效性.  相似文献   

14.
研究了项目调度问题及其优化算法,在对调度问题作了详细分类的基础上,对各种调度问题的优化算法做出.总结,并针对目前各种调度模型存在的不足,提出了均衡优化调度和可持续发展调度等新的调度目标。  相似文献   

15.
Multiclass Combined Models for Urban Travel Forecasting   总被引:1,自引:1,他引:1  
Progress in formulating, solving and implementing models with multiple user classes that combine several travel choices into a single, consistent mathematical formulation is reviewed. Models in which the travel times and costs on the road network are link flow-dependent are considered; such models seek to represent congestion endogenously. The paper briefly summarizes the origins of this field in the 1950s and its evolution through the development of solution algorithms in the 1970s. The primary emphasis of the review is on the implementation and application of multiclass models. The paper concludes with a brief discussion of prospects for improved solution algorithms.  相似文献   

16.
In this paper we consider the solution of large-scale market equilibrium problems with linear transaction costs which can be formulated as strictly convex quadratic programming problems, subject to supply and demand constraints. In particular, we introduce two new classes of progressive equilibration algorithms, which retain the simplicity of the original cyclic ones in that at each step either the supply or demand market equilibrium subproblem can be solved explicitly in closed form. However, rather than equilibrating the markets in cyclic manner, the next market to be equilibrated is selected in a more strategic fashion.We then provide qualitative results for the entire family of progressive equilibration algorithms, i.e., the rate of convergence and computational complexity. We discuss implementation issues and give computational results for large-scale examples in order to illustrate and give insights into the theoretical analysis. Furthermore, we show that one of the new classes of algorithms, the good-enough one, is computationally the most efficient. Theoretical results are important in that the relative efficiency of different algorithms need no longer be language, machine, or programmer dependent. Instead, the theory can guide both practitioners and researchers in ensuring that their implementation of these algorithms is, indeed, good.Since an equivalent quadratic programming problem arises in a certain class of constrained matrix problems, our results can be applied there, as well. Finally, since more general asymmetric multicommodity market equilibrium problems can be solved as series of the type of problems considered here, the result$ are also applicable to such equilibrium problems.  相似文献   

17.
In the pursuit to study the parameterization problem of molecular models with a broad perspective, this paper is focused on an isolated aspect: It is investigated, by which algorithms parameters can be best optimized simultaneously to different types of target data (experimental or theoretical) over a range of temperatures with the lowest number of iteration steps. As an example, nitrogen is regarded, where the intermolecular interactions are well described by the quadrupolar two-center Lennard-Jones model that has four state-independent parameters. The target data comprise experimental values for saturated liquid density, enthalpy of vaporization, and vapor pressure. For the purpose of testing algorithms, molecular simulations are entirely replaced by fit functions of vapor-liquid equilibrium (VLE) properties from the literature to assess efficiently the diverse numerical optimization algorithms investigated, being state-of-the-art gradient-based methods with very good convergency qualities. Additionally, artificial noise was superimposed onto the VLE fit results to evaluate the numerical optimization algorithms so that the calculation of molecular simulation data was mimicked. Large differences in the behavior of the individual optimization algorithms are found and some are identified to be capable to handle noisy function values.  相似文献   

18.
We present an auction-based algorithm for computing market equilibrium prices in a production model, in which producers have a single linear production constraint, and consumers have linear utility functions. We provide algorithms for both the Fisher and Arrow–Debreu versions of the problem.  相似文献   

19.
This paper is concerned with anti-disturbance Nash equilibrium seeking for games with partial information. First, reduced-order disturbance observer-based algorithms are proposed to achieve Nash equilibrium seeking for games with first-order and second-order players, respectively. In the developed algorithms, the observed disturbance values are included in control signals to eliminate the influence of disturbances, based on which a gradient-like optimization method is implemented for each player. Second, a signum function based distributed algorithm is proposed to attenuate disturbances for games with second-order integrator-type players. To be more specific, a signum function is involved in the proposed seeking strategy to dominate disturbances, based on which the feedback of the velocity-like states and the gradients of the functions associated with players achieves stabilization of system dynamics and optimization of players’ objective functions. Through Lyapunov stability analysis, it is proven that the players’ actions can approach a small region around the Nash equilibrium by utilizing disturbance observer-based strategies with appropriate control gains. Moreover, exponential (asymptotic) convergence can be achieved when the signum function based control strategy (with an adaptive control gain) is employed. The performance of the proposed algorithms is tested by utilizing an integrated simulation platform of virtual robot experimentation platform (V-REP) and MATLAB.   相似文献   

20.
研究并建立了网络化的复杂化学平衡计算系统,可以进行复杂化学反应平衡组成计算以及用于分析温度、压力对平衡组成的影响。系统不但具有多种平衡组成计算模式和三种新型通用有效的计算方法,而且具有多样化的结果显示方式,能够直接对计算结果进行评价。经过多种复杂体系的计算比较,提出了算法选用的建议。  相似文献   

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