共查询到20条相似文献,搜索用时 31 毫秒
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Pieter H. de Vries 《连接科学》2020,32(3):292-332
In order to find conditions for biologically plausible, cognitive self-organisation, an adequate representation of the final stage of this process is crucial. The implications of this assumption are analysed for the area of visual-word processing, in particular for position-specific top-down processes from a word – to a letter representation. These processes pose a problem to reviewed models of word reading and computational models in general. A solution in the form of a conceptual network is proposed. In this general model for cognitive brain processes, neural binding of identity and location and of identity and position play a fundamental role: temporary connections emerge during word recognition and are reactivated later, when a letter at given position has to be identified. It is shown how modules active in word recognition are “re-used” in letter identification. In simulations, the role of a critical threshold of cell-assemblies is shown and the selective propagation of activation loops at task-dependent time scales. Requirements for prospective studies on cognitive self-organisation and relations with new empirical work on visual-word processing are discussed. 相似文献
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A hybrid reasoning model was proposed in which CBR (case-based reasoning) was applied to the conceptual design and RBR (rule-based reasoning) was applied to the detailed design after research of the design process and domain knowledge of the acre-engine turbine blade investment casting mold design field. In the conceptual design stage, the representation and retrieval technologies were researched which improve the retrieval efficiency. Meanwhile, RBR was used to modify the retrieval result. The experimentation shows that the approach in this study can be used to obtain a more satisfactory design result. 相似文献
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开发了一套锤上模锻计算机辅助工艺设计专家系统软件,根据锤上模锻的工艺特点,采用合理的知识表达形式,建立起具有专家水平的知识库,以黑板为中介实现过程化推理与反向推理相结合的推理方式,适应了本系统多层次、多目标的需要,并采用半自动知识获取形式完成对系统的维护。本文在西文操作系统下实现了汉字界面技术,使程序运行快速、灵活,具有很强的实用性。 相似文献
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从分析焊接裂纹的特点出发,提出了基于知识库的焊接裂纹诊断专家系统。文中给出了系统总体结构模型和面向对象模型,根据系统要求建立了数据库、积累案例形成案例库;获取专家结构模型和面向对象模型,根据系统要求建立了数据库、积累案例形成案例库;获取专家经验及领域知识建立了规则库;依据知识层次结构建立了模型库,这四库一体化形成专家系统。文中介绍了基于案例、基于规则和基于模型的诊断推理,比较了各种诊断理方法的优、缺点,并提出了基于案例、规则和模型的混合推理,其优点在于能充分发挥各种推理方法的优势,克服各自存在的不足,能量大限度地找到问题的解。文中讨论了贴近度的定义、表示和计算以及规则表示等问题。最后文中给出了系统的功能和实现方法。应用证明基于知识训的焊接裂纹诊断专家可以得到与专家同样的诊断结果。 相似文献
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An expert system for generation of machine inputs for laser-based multi-directional metal deposition 总被引:1,自引:1,他引:0
Rajeev Dwivedi Radovan Kovacevic 《International Journal of Machine Tools and Manufacture》2006,46(14):1811-1822
Laser-based multi-directional metal deposition (LBMDMD) is a very effective way of fabricating a part directly from its digital model. The method, however, requires a lot of human intervention during the process planning. Driven by already developed expert systems for the process planning in Computer Aided Design (CAD) and manufacturing, this paper intends to suggest a task framework for the automation of the process planning for LBMDMD using principles of Artificial Intelligence (AI). The process can be divided into distinct steps, and geometric reasoning can be applied to determine a set of facts and rules for the automation. The principles of first order logic are applied for the representation and further simplification of the process into a set of “if–then” based rules. This paper explains the framework, the facts, and the rule base used for the process planning. 相似文献
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基于故障层次模型的集成神经网络诊断 总被引:1,自引:0,他引:1
复杂系统具有层次结构特点,基于故障层次模型的诊断策略是复杂系统故障诊断可行和有效方法.集成神经网络模型以故障层次模型为参考,可以大大缩小诊断推理的求解空间,最终快速定位发生故障的根本部位.集成神经网络的模型结构为多模型或方法集成应用提供了一个良好的融合机制.基于模糊ART神经网络及BP神经网络构建的集成神经网络更进一步具有发现新故障的能力,且能够对故障引发部位实现精确诊断和定位. 相似文献
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In recent years, a growing number of researchers have proposed that analogy is a core component of human cognition. According to the dominant theoretical viewpoint, analogical reasoning requires a specific suite of cognitive machinery, including explicitly coded symbolic representations and a mapping or binding mechanism that operates over these representations. Here we offer an alternative approach: we find that analogical inference can emerge naturally and spontaneously from a relatively simple, error-driven learning mechanism without the need to posit any additional analogy-specific machinery. The results also parallel findings from the developmental literature on analogy, demonstrating a shift from an initial reliance on surface feature similarity to the use of relational similarity later in training. Variants of the model allow us to consider and rule out alternative accounts of its performance. We conclude by discussing how these findings can potentially refine our understanding of the processes that are required to perform analogical inference. 相似文献
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The experimental measurement of the group and phase velocities of some circumferential waves propagating around a thin elastic tube is a still complex operation. In this study, we show that the dispersion velocity can be determined from a time–frequency representation. We use the Wigner–Ville method by virtue of its interesting properties. On some time–frequency images, the symmetric (S0) and antisymmetric (A1) circumferential waves are identified. The group velocity dispersion estimated from these images is compared with that computed by the proper mode theory method. A good agreement is obtained. The phase velocity is also determined from the group velocity. 相似文献
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Al-Si合金活塞金属型铸造工艺和模具设计智能化 总被引:1,自引:0,他引:1
为了开发Al-Si合金活塞金属型铸造工艺和模具智能化设计系统,在对国内外先进设计经验总结、归纳的基础上,采用面向对象的知识表达方法,建立了模块化的知识库。系统应用了基于实例的推理技术并建立了实例库和实例原型库。通过开发的文件接口程序,完成了一般设计型专家系统与传统CAD系统的连接,实现了智能化设计。通过与现场使用的设计方案比较,验证了本系统的有效性和实用性。 相似文献
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Zuntong Wang Zhanqiang Liu Xing Ai 《International Journal of Machine Tools and Manufacture》2003,43(13):1347-1353
Applying case-based reasoning in high-speed machining can utilize previous cases and experience in machining a new work piece. This is helpful in overcoming the shortage of available high-speed machining data, and has significance for extending the application of HSM technology. For case representation, a model of case in HSM with relational data mode is proposed in the paper. With analysis of the characteristics of attributes and domain knowledge of HSM, the local similarities of case attributes are sorted into four classes: the numerical type, the enumerative type, the independent type, and the dependent type. The global similarity of cases is calculated by a composite similarity measure. 相似文献
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In this paper, we describe the Parallel Race Network (PRN), a race model with the ability to learn stimulus-response associations using a formal framework that is very similar to the one used by the traditional connectionist networks. The PRN assumes that the connections represent abstract units of time rather than strengths of association. Consequently, the connections in the network indicate how rapidly the information should be sent to an output unit. The decision is based on a race between the outputs. To make learning functional and autonomous, the Delta rule was modified to fit the time-based assumption of the PRN. Finally, the PRN is used to simulate an identification task and the implications of its mode of representation are discussed. 相似文献