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991.
In this study, a synthesis method for a non-integer periodic function generator of a four-bar mechanism using a Haar wavelet is presented. Using wavelet theory, the mathematical model for the output of a four-bar mechanism is established. Next, the characteristics of the four-bar mechanism output variable are described by the wavelet feature parameters; the relationship of the wavelet feature parameters between the output and its translation or dilation is also investigated. Based on this finding, three numerical atlas databases comprising of 203,500 groups of basic dimensional types of planar four-bar mechanisms, 148,995 groups of basic dimensional types of spherical four-bar mechanism and 11,175 groups of basic dimensional types of planar slider–crank mechanism are compiled. According to the internal relationship between the wavelet feature parameters, the sizes of the objective mechanism can be obtained using fuzzy recognition. Based on a genetic algorithm, optimization of the link parameters can be realized. Three examples are presented to demonstrate the efficacy and practicality of the proposed theory.  相似文献   
992.
In this paper, a new hybrid learning algorithm is introduced to evolve the flexible beta basis function neural tree (FBBFNT). The structure is developed using the Extended Genetic Programming (EGP) and the Beta parameters and connected weights are optimized by the Hybrid Artificial Bee Colony algorithm. This hybridization is essentially based on replacing the random Artificial Bee Colony (ABC) position with the guided Opposite-based Particle Swarm Optimization (OPSO) position. Such modification can minimize the delay which might be lead by the random position, in reaching the global solution. The performance of the proposed model is evaluated for benchmark problems drawn from time series prediction area and is compared with those of related methods.  相似文献   
993.
液压泵退化特征提取是实现故障预测的关键环节。在液压泵性能退化过程中,其振动信号复杂度高、非线性强,难以有效地提取退化特征,为此,本文提出一种基于敏感分量融合的退化特征提取方法。采用改进局部特征尺度分解(ILCD)方法对振动信号进行分解,并利用贝叶斯信息准则与所构建的敏感因子,对内禀尺度分量进行筛选,以减少干扰分量的影响,得到敏感分量,有效抓取特征信息;在此基础上,引入离散余弦变换代替传统复合谱分析中的傅里叶变换,提出离散余弦变换-复合谱(DCS)算法,以解决信息遗漏问题,并利用DCS对敏感分量进行融合,提取复合谱熵作为退化特征,以提高对退化过程的表征能力;最后,通过对液压泵性能退化试验实测振动信号的应用分析,验证了该方法的有效性。  相似文献   
994.
Heavy oil and extra heavy oil resources comprise about 75% of petroleum resources. The most important characteristic of heavy oils is their viscosity. Consequently, to extract and prepare these kinds of crude oil for use, great emphasis should be put on viscosity. The present study highlights the application of intelligent model named radial basis function (RBF) network optimized by genetic algorithm for estimation of diluted heavy oil viscosity in presence on kerosene. The input parameters of model were temperature and mass fraction of kerosene. The output of model was viscosity of heavy oil. Genetic algorithm was utilized to optimize the tuning parameters of RBF model. The outcomes of this study showed that the proposed model is accurate in estimation of target data.  相似文献   
995.
Fabrication of metal matrix composite materials by using the traditional casting process is a very promising task of developing near net shape products at a very low cost. Among these casting processes, the stir-casting technique has fine microstructures because of fast cooling, less porosity and good quality bonding among particle and the base matrix alloy. The major aim of this present paper is to fabricate titanium carbide reinforced metal matrix composite (MMC) by using micron sized activated charcoal powder, to get react with titanium material for producing TiC intermetallic particles in the Al–4.5%Cu matrix by in-situ technique so as to produce Al–4.5%Cu–5%TiC MMC, with the intention of finding the optimum processing parameter i.e. pouring temperature, stirring speed in liquid melt-stirring process, reaction time with the aim of achieving better microstructure and mechanical properties, i.e. micro-hardness, toughness and ultimate tensile strength by using an efficient grey based differential evolution algorithm. Mechanical properties of optimum processing condition are verified by doing confirmation tests. ANOVA analysis is performed to analyze the role of each factor on multiple performance characteristics and it was found that stirrer rotational speed and reaction time is playing a key role in affecting the mechanical property. Additionally, to predict the response parameters regression equations were developed and the validity of regression model is tested by plotting scatter diagram. Finally microstructure study has been performed for the optimal sample by using optical microscope.  相似文献   
996.
This paper describes the development of an exact allocation-based solution algorithm for the facility location and capacity acquisition problem (LCAP) on a line with dense demand data. Initially, the n-facility problem on a line is studied and formulated as a dynamic programming model in the allocation decision space. Next, we cast this dynamic programming formulation as a two-point boundary value problem and provide conditions for the existence and uniqueness of solutions. We derive sufficient conditions for non-empty service regions and necessary conditions for interior facility locations. We develop an efficient exact shooting algorithm to solve the problem as an initial value problem and illustrate on an example. A computational study is conducted to study the effect of demand density and other problem parameters on the solutions.  相似文献   
997.
In this paper, thermodynamic analysis is carried out for a geothermal Kalina cycle employed in Husavic power plant. Afterwards, the optimum operating conditions in which the cycle is at its best performance are calculated. In order to reach the optimum thermal and exergy efficiencies of the cycle, Artificial Bee Colony (ABC) algorithm, a new powerful multi-objective and multi-modal optimization algorithm, is conducted. Regarding the mechanism of ABC algorithm, convergence speed and precision of solutions have been remarkably improved when compared to those of GA, PSO and DE algorithms. Such a relative improvement is indicated by a limit parameter and declining probability of premature convergence. In this research, exergy efficiency including chemical and physical exergies and thermal efficiency are chosen as the objective functions of ABC algorithm where optimum values of the efficiencies for the Kalina cycle are found to be 48.18 and 20.36%, respectively, while the empirical thermal efficiency of the cycle is about 14%. At the optimum thermal and exergy efficiencies, total exergy destruction rates are respectively 4.17 and 3.48 MW. Finally, effects of the separator inlet pressure, temperature, basic ammonia mass fraction and mass flow rate on the first and second law efficiencies are investigated.  相似文献   
998.
基于遗传算法的大厂矿区地震定位研究   总被引:1,自引:0,他引:1  
基于遗传算法对大厂矿区的地震进行重新定位。为验证该方法在大厂矿区的应用效果,首先对已知的5次人工爆破进行定位,得出平均定位水平误差在146m范围内(矿区台网定位水平误差为500m),进而对大厂矿区的81次ML1.0级以上地震进行重新定位,结果表明:大厂矿震主要呈北西向展布,且主要集中在大厂断裂右侧;较大地震均与大厂断裂呈平行状分布,推断其附近可能有隐伏断层存在;大厂矿区地震主要受北西向断层的影响,受北东向断层的影响不大。定位后震源平均深度为2.8km,最大深度6.5km,最小深度1.5km。  相似文献   
999.
针对快速门在恶劣环境下使用存在的问题,采用合理的解决方案对快速门进行改造,解决了现场灰尘大造成雷达感应器失灵和现场有强风造成门帘脱离轨道的问题,开拓了快速门的应用领域。  相似文献   
1000.
In this paper a three echelon supply chain with multiple distribution centers, production sites and suppliers is modeled. For this supply chain several commodities with defined items is produced. The model is categorized as a capacitated facility location model. The hierarchical approach is used to modeling and based on decision types the model is divided into two levels. The solution approach is based on the Lagrangian Relaxation approach, improved by an efficient heuristic to solve complex sub-problems. Computational results indicated that the proposed method yields high-quality solutions within a reasonable computational time for various real size problems.  相似文献   
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