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891.
通过对空调产品颜色(塑料着色剂、钣金粉末涂料)特性及生产方式的分析,介绍产品颜色通用化管理体系及建立方法。通过思路和方法的创新,建立一套行之有效且效益可有效评估的通用化颜色管控体系。 相似文献
892.
893.
894.
De Weerd Peter; Desimone Robert; Ungerleider Leslie G. 《Canadian Metallurgical Quarterly》2003,117(6):1441
The authors tested the spatial generalization of shape and color discriminations in 2 monkeys, in which 3 visual field quadrants were affected, respectively, by lesions in area V4, TEO, or both areas combined. The fourth quadrant served as a normal control. The monkeys were trained to discriminate stimuli presented in a standard location in each quadrant, followed by tests of discrimination performance in new locations in the same quadrant. In the quadrant affected by the V4 + TEO lesion, the authors found temporary but striking deficits in spatial generalization of shape and color discriminations over small distances, suggesting a contribution of areas V4 and TEO to short-range spatial generalization of visual skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
895.
Researchers know little about whether very young children can recognize objects originally introduced to them in a picture book when they encounter similar looking objects in various real-world contexts. The present studies used an imitation procedure to explore young children's ability to generalize a novel action sequence from a picture book to novel test conditions. The authors found that 18-month-olds imitated the action sequence from a book only when the conditions at testing matched those at encoding; altering the test stimuli or context disrupted imitation (Experiment 1A). In contrast, the 24-month-olds imitated the action sequence with changes to both the test context and stimuli (Experiment 1B). Moreover, although the 24-month-olds exhibited deferred imitation with no changes to the test conditions, they did not defer imitation with changes to the context and stimuli (Experiment 2). Two factors may account for the pattern of results: age-related changes in children's ability to utilize novel retrieval cues as well as their emerging ability to understand the representational nature of pictures. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
896.
Xiaofei He 《International Journal of Software and Informatics》2013,7(3):357-358
In many information analysis tasks, one is often confronted with thousands to millions dimensional data, such as images, documents, videos, web data, bioinformatics data, etc. Conventional statistical and computational tools are severely inadequate for processing and analysing high-dimensional data due to the curse of dimensionality, where we often need to conduct inference with a limited number of samples. On the other hand, naturally occurring data may be generated by structured systems with possibly much fewer degrees of freedom than the ambient dimension would suggest.
Recently, various works have considered the case when the data is sampled from a submanifold embedded in the much higher dimensional Euclidean space. Learning with full consideration of the low dimensional manifold structure, or specifically the intrinsic topological and geometrical properties of the data manifold is referred to as manifold learning, which has been receiving growing attention in our community in recent years.
This special issue is to attract articles that (a) address the frontier problems in the scientific principles of manifold learning, and (b) report empirical studies and applications of manifold learning algorithms, including but not limited to pattern recognition, computer vision, web mining, image processing and so on. A total of 13 submissions were received. The papers included in this special issue are selected based on the reviews by experts
in the subject area according to the journal''s procedure and quality standard. Each paper is reviewed by at least two reviewers and some of the papers were revised for two rounds according to the reviewers'' comments.
The special issue includes 6 papers in total: 3 papers on the foundational theories of manifold learning, 2 papers on
graph-based methods, and 1 paper on the application of manifold learning to video compression. The papers on the foundational theories of manifold learning cover the topics about the generalization ability of manifold learning, manifold ranking, and multi-manifold factorization.
In the paper entitled ``Manifold Learning: Generalizing Ability and Tangential Proximity'', Bernstein and Kuleshov propose a tangential proximity based technique to address the generalized manifold learning problem. The proposed method ensures not only proximity between the points and their reconstructed values but also proximity between the corresponding tangent spaces.
The traditional manifold ranking methods are based on the Laplacian regularization, which suffers from the issue that the solution is biased towards constant functions. To overcome this issue, in the paper entitled ``Manifold Ranking using Hessian Energy'', Guan et al. propose to use the second-order Hessian energy as regularization for manifold ranking.
In the paper entitled ``Multi-Manifold Concept Factorization for Data Clustering'', Li et al. incorporate the multi-manifold ensemble learning into concept factorization to better preserve the local structure of the data, thus yielding more satisfactory clustering results.
The papers on graph-based methods cover the topics about label propagation and graph-based dimensionality reduction.
In the paper entitled ``Bidirectional Label Propagation over Graphs'', Liu et al. propose a novel label propagation algorithm to propagate labels along positive and negative edges in the graph. The construction of the graph is novel against the conventional approach by incorporating the dissimilarity among data points into the affinity matrix.
In the paper entitled ``Locally Regressive Projections'', Lijun Zhang proposes a novel graph-based dimensionality reduction method that captures the local discriminative structure of the data space. The key idea is to fit a linear model locally around each data point, and then use the fitting error to measure the performance of dimensionality reduction.
In the last paper entitled ``Combining Active and Semi-Supervised Learning for Video Compression'', motivated from manifold regularization, Zhang and Ji propose a machine learning approach for video compression. Active learning is used to select the most representative pixels in the encoding process, and semi-supervised learning is used to recover the color video in the decoding process. One remarking property of this approach is that the active learning algorithm shares the same loss function as the semi-supervised learning algorithm, providing a unified framework
for video compression.
Many people have been involved in making this special issue possible. The guest editor would like to express his gratitude to all the contributing authors for their insightful work on manifold learning. The guest editor would like to thank the reviewers for their comments and useful suggestions in order to improve the quality of the papers. The guest editor would also like to thank Prof. Ruqian Lu, the editor-in-chief of the International Journal of Software and Informatics, for providing the precious opportunity to publish this special issue. Finally, we hope the reader will enjoy this special issue and find it useful. 相似文献
897.
基于改进粒子群-径向基神经网络模型的短期电力负荷预测 总被引:2,自引:0,他引:2
为了准确、快速、高效地预测电网短期负荷,提出了改进的粒子群–径向基神经网络算法。用改进的粒子群算法训练径向基神经网络,实现了径向基函数神经网络的参数优化。建立了短期电力负荷预测模型,综合考虑气象、天气、日期类型等影响负荷的因素进行短期负荷预测。算例结果表明,该算法优于径向基神经网络法和粒子群–径向基网络算法,克服了径向基网络和粒子群优化方法的缺点,改善了径向基神经网络的泛化能力,输出稳定,预测精度高,收敛速度快,平均百分比误差可控制在1.2%以内。 相似文献
898.
899.
随着交直流混联电网规模的扩大与电力电子化设备的大规模并网,以新能源为主体的新型电力系统的动态特性愈加复杂。物理模型的机理可解释性与数据模型的特性拟合能力具有很强的互补性。如何将融合模型的构建从定性分析向定量分析提升亟待深入研究。文中基于电力系统中数据方法与物理方法的特点,针对4种典型数据-物理融合模型分析了其相对应的应用场景;以并联模式为研究对象,分别对比分析了并联模式与单一物理模型和单一数据模型的泛化误差,并提出了融合模型参数的选取方法;推导了并联模式下融合模型的泛化误差上限,并提出了改进融合模型性能的可行性建议;最后,结合暂态功角稳定问题验证了所提假设与结论的合理性。 相似文献
900.
一种考虑属性权重的隐私保护数据发布方法 总被引:1,自引:0,他引:1
k-匿名模型是数据发布领域用于对原始待发布数据集进行匿名处理以阻止链接攻击的有效方法之一,但已有的k-匿名及其改进模型没有考虑不同应用领域对匿名发布表数据质量需求不同的问题.在特定应用领域不同准码属性对基于匿名发布表的数据分析任务效用的贡献程度是不同的,若没有根据发布表用途的差异区别处理各准码属性的泛化过程,将会导致泛化后匿名发布表数据效用较差、无法满足具体数据分析任务的需要.在分析不同应用领域数据分析任务特点的基础上,首先通过修正基本ODP目录系统建立适用于特定问题领域的概念泛化结构;然后在泛化过程中为不同准码属性的泛化路径设置权重以反映具体数据分析任务对各准码属性的不同要求;最后设计一种考虑属性权重的数据匿名发布算法WAK(QI weight-aware k-anonymity),这是一种灵活地保持匿名发布表数据效用的隐私保护问题解决方案.示例分析和实验结果表明,利用该方案求解的泛化匿名发布表在达到指定隐私保护目标的同时,能够保持较高的数据效用,满足具体应用领域特定数据分析任务对数据质量的要求. 相似文献