共查询到20条相似文献,搜索用时 189 毫秒
1.
基于多相关因素的汽车保有量预测神经网络方法 总被引:7,自引:1,他引:7
将神经网络技术用于汽车保有量预测,建立基于双BP神经网络的多相关因素汽车保有量预测模型。以呼和浩特市汽车保有量预测为例,详细介绍汽车保有量神经网络预测模型的操作过程,并证实了该方法的可行性和可靠性。 相似文献
2.
基于神经网络BP算法的出租汽车保有量预测法 总被引:1,自引:0,他引:1
介绍了出租车保有量神经网络预测模型的建立.以南京市的实际数据为检测依据,论证了该模型应用于城市出租汽车保有量预测的可行性,并对该市2005~2008年的出租汽车保有量进行了预测;该预测模型与传统模型进行预测对比的结果表明,由于神经网络在处理非线性系统方面的优越性,该预测模型在交通预测方面具有较高的计算精度. 相似文献
3.
为提高短时交通流预测的精度,提出利用BP神经网络、RBF神经网络和ARIMA模型构建组合预测模型,该组合预测模型利用最优化原理进行权系数的分配,并且满足分配到的权值始终具有实际意义。通过对分配的权系数进行显著性检验,以确保组合预测模型中选用的单项预测方法显著相关。通过实例分析,验证了组合预测模型的有效性,结果表明,相比较单一的预测模型,组合预测模型具有更高的预测精度。 相似文献
4.
5.
基于GIS的机群优化配置系统 总被引:1,自引:1,他引:0
在大型工程的施工中,需要对施工机械(车辆)进行优化配置和调度,才能减少消耗,缩短工期和提高效率。本文从工程施工的一般性出发,以GIS技术为支撑,提出了机群的优化配置系统,该系统能够结合具体的特点,动态地配置,调度施工机械(车辆),从而达到提高施工的质量,效率,缩短工期,节省成本等。 相似文献
6.
7.
为了解决工程造价指数难以预测非线性结构、数据拟合难度大、预测模型参数求解过于固定化、预测模型可靠性不高等问题,文中在混沌时间序列理论的基础上,结合机器学习算法支持向量机(SVM)技术和BP神经网络算法,提出混沌SVM与BP神经网络组合预测模型。实例研究证明,该组合预测模型的精度比SVM预测模型、混沌SVM预测模型、BP神经网络预测模型和GM(1,1)预测模型的高,具有拟合非线性和预测线性波动的能力,可用于工程造价指数预测。 相似文献
8.
崔崇学 《内蒙古公路与运输》2004,(2):20-22
从综合分析公路工程机械化施工系统施工进度和施工成本人手,重点介绍了公路工程机械化施工主导机械和辅助机械的具体确定方法。根据严格的数学推导,得出“公路工程机械化施工的进度、成本控制,实际上就是对公路工程机械化施工系统的系统生产率进行控制”的结论。 相似文献
9.
水泥混凝土路面机械化施工系统设计与评价 总被引:3,自引:0,他引:3
根据水泥混凝土路面机械化施工系统机械运行的一般规律,提出了系统设计与评价的标准,方法和步骤,结合深(圳)汕(头)高等级公路水泥混凝土路面机械化施工的实践,给出了系统评价的实例。 相似文献
10.
首先分析了材料性能对桥梁承载力的影响,并采用有限元方法扩大既有桥梁数据,建立相应的数据库。然后,通过MATLAB建立BP神经网络模型对数据库进行训练完成桥梁承载力权重系数估算,并构建神经网络预测模型实现承载力预测,通过对比验证预测模型的准确性。最后,研究利用BIM二次开发研发桥梁承载力评估与预测系统。结果表明,随着桥梁使用年限的增长,钢筋对桥梁承载力的贡献相较于混凝土而言明显降低,材料退化对抗弯承载力影响最大;桥梁配筋面积对抗弯、抗剪承载力影响最大;当数据库的数据较少且预测精度要求较高时,采用多层隐藏层神经网络预测模型更有效;当数据库的数据庞大且预测精度要求不高时,采用GA-BP神经网络预测模型更有效。 相似文献
11.
阐述了用于珩磨的自动测量系统的基本组成工作原理,另外,从技术发展的角度出发,对现代自动测量技术在珩磨加工中的衫用进行了分析;指出了珩磨自动测量是实现加工自动化的一个重要环节,对提高生产率,减轻劳动强度,降低废品率有十发显的作用。 相似文献
12.
针对工程机械中很多追求生产率和发动机功率的利用率,而不以作业质量作为主要性能指标的多装置复合作业型工程机械,提出了一种基于DA控制理论的液压系统控制策略。该方法能够解决发动机功率在不同工作装置之间的分配,使发动机功率输出保持在最大,简单可靠。 相似文献
13.
Design of conformal cooling channels for an automotive part 总被引:2,自引:0,他引:2
The cooling system plays a crucial role in determining the productivity and quality of an injection molding process. With
the current growth of Solid Freeform Fabrication (SFF) techniques, mold designers have been striving for not only improvement
in cooling system performance but also for a method to do so automatically. In this paper, a method is proposed for developing
a conformal cooling system that facilitates uniform cooling over the entire mold surface with minimum cycle time. Based on
the temperature distribution after the filling stage, the mold surface is split into zones which will be cooled by optimized
subconformal channels obtained from the optimization process. The optimization process in which the objective function is
stated as minimization of the cooling time with boundaries ensuring a realistic design will optimize the cooling system layout
in terms of cooling channel size and location. Finally, all subcooling channels are combined to generate the entire conformal
cooling system for the injection mold. 相似文献
14.
Maksym Spiryagin Peter Wolfs Colin Cole Sebastian Stichel Mats Berg Plöchl Manfred 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(8):1241-1264
The main task for heavy haul railway operators is to reduce the cost of exported minerals and enhance the long-term viability of rail transport operations through increasing productivity by running longer and heavier trains. The common opinion is that this is achievable by means of implementation of high adhesion locomotives with advanced AC traction technologies. Modern AC high adhesion locomotives are very complex mechatronic systems and can be designed with two alternative traction topologies of either bogie or individual axle controls. This paper describes a modelling approach for these two types of AC traction systems with the application of an advanced co-simulation methodology, where an electrical system and a traction algorithm are modelled in Matlab/Simulink, and a mechanical system is modelled in a multibody software package. Although the paper concentrates on the analysis of the functioning for these two types of traction control systems, the choice of reference slip values also has an influence on the performance of both systems. All these design variations and issues have been simulated for various adhesion conditions at the wheel–rail interface and their influence on the high traction performance of a locomotive equipped with two three-axle bogies has been discussed. 相似文献
15.
Disruptions in automated manufacturing systems for machining automotive parts caused by system changes and disturbances reduce the productivity, and increase the downtime as well as the cost of products. To cope with these challenges, the paper presents a biology inspired manufacturing system (Bio-MS). The model of Bio-MS is inherited from the organization of the living systems in biology and nature such as ant colony, school of fish, bee’s foraging behaviors, and so on. In which, the resources of the manufacturing system are considered as biological organisms, which are autonomous entities so that the manufacturing system has the advanced characteristics inspired from biology such as self-adaptation, self-diagnosis, and self-healing. To realize the Bio-MS, the cognitive agent and swarm intelligence were proposed. The disturbances happening when machining the transmission cases at an automotive company in Korea were analyzed to classify them and to find out the corresponding management methods. Currently, the system utilization was too low due to the manual recovery, only 70–76 percent of total production time is used for manufacturing and the rest of the time is wasted in different disturbances. The Bio-MS with autonomous behaviors adapts efficiently to the changes of the manufacturing environment. It enables to increase the system utilization more than 80 percent. 相似文献
17.
18.
针对汽车发动机舱盖的结构特点和技术要求,采用斜顶杆抽芯机构,解决了内部结构不规则,有倒扣、脱模困难等问题.该产品尺寸较大,注塑充填同样存在困难,为保证产品充填质量,节约材料,提高生产率,故采用多点冷热流道相结合的浇注系统. 相似文献
19.
不利气象条件给公路交通畅通与运行安全带来了巨大的不利影响,为应对这一挑战,欧美发达国家部署和实施了道路气象信息系统,借助该系统,公路管理部门能够根据实时的和预测道路天气情况来管理交通,确保道路的畅通与运行安全,此外,这一系统还能够为冬季道路养护提供辅助决策,降低用于道路冰雪控制的成本。我国在近几年加快了道路气象信息系统的实施步伐,也出现了一些有代表性的应用案例。本文重点介绍了道路气象信息系统及其应用的历史发展沿革,介绍了欧美部分国家在这方面的应用状况与特点,在此基础上,作者对国外的成功经验进行了总结,以期为国内道路气象信息系统的发展提供借鉴与参考。 相似文献
20.
文章立足于天津汽车产业发展现状,阐述了天津汽车工业的生产、创新及盈利能力,并在此基础上分析其面临的机遇与挑战。理性分析天津汽车产业所处的内外环境,有助于其抓住机遇,正确定位,促使天津汽车工业健康有序地发展。 相似文献