共查询到20条相似文献，搜索用时 656 毫秒
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支持向量机是一种基于统计学习理论的机器学习方法,针对小样本情况表现出了优良的性能,目前被广泛应用于模式识别、函数回归、故障诊断等方面。这里主要研究支持向量机分类问题,着重讨论了以下几个方面的内容。首先介绍了支持向量机分类器算法,并将其应用于数据分类,取得了较高的准确率,所用数据来自于UCI数据集。仿真结果表明该算法具有较快的收敛速度和较高的计算精度。 相似文献
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支持向量机(SVM)是建立在统计学习理论基础上的一种通用的研究机器学习规律的方法。它具有很强的学习能力和泛化能力,可以有效地处理分类,回归等问题。SVM在处理非线性问题时,通过使用一个核函数来解决复杂计算问题。最小二乘支持向量机(LS_SVM)是SVM的一种改进,它提高了求解问题的速度和收敛精度。本文以太阳黑子为数据集,基于LS_SVM工具,使用了支持向量回归算法(SVR),实现了太阳黑子活动的预测。 相似文献
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支持向量机是一种有良好发展前景的学习机器。针对支持向量机训练过程中特征选择和参数优化的问题,提出一种基于蝙蝠算法和禁忌搜索算法相结合的算法的支持向量机特征选择和参数优化算法。将禁忌搜索算法理论引入蝙蝠算法中,可以有效提高BA算法的收敛速度和精度,得到更优的支持向量机模型。UCI标准数据集的分类实验结果表明,与基本的网格搜索,遗传算法等比较,TSBA算法可以获得更高的分类准确率和更好的稳定性。 相似文献
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如何准确分析用户行为,向用户提供满意的网页信息,一直以来都是个性化信息推荐系统设计的目标。本文在分析现有个性化信息推荐模型的基础上,针对以往研究在推荐兴趣时仅根据语义相关度进行协助性信息推荐,而忽略用户行为规律所包含的潜在兴趣信息的不足,尝试提出一个结合Web语义挖掘和FP-tree规则发现技术的个性化信息推荐模型。该模型利用本体对语义的明确化描述,在挖掘用户行为信息时获取用户兴趣偏好的语义信息,并利用FP-tree技术根据以获取的语义信息推理出用户兴趣行为模式,从而在信息推荐时不仅能准确理解用户兴趣偏好,也能根据用户潜在兴趣规律,推荐给用户更全面的网页信息。 相似文献
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Modeling user profiles is a necessary step for most information filtering systems – such as recommender systems – to provide personalized recommendations. However, most of them work with users or items as vectors, by applying different types of mathematical operations between them and neglecting sequential or content-based information. Hence, in this paper we study how to propose an adaptive mechanism to obtain user sequences using different sources of information, allowing the generation of hybrid recommendations as a seamless, transparent technique from the system viewpoint. As a proof of concept, we develop the Longest Common Subsequence (LCS) algorithm as a similarity metric to compare the user sequences, where, in the process of adapting this algorithm to recommendation, we include different parameters to control the efficiency by reducing the information used in the algorithm (preference filter), to decide when a neighbor is considered useful enough to be included in the process (confidence filter), to identify whether two interactions are equivalent (δ-matching threshold), and to normalize the length of the LCS in a bounded interval (normalization functions). These parameters can be extended to work with any type of sequential algorithm.We evaluate our approach with several state-of-the-art recommendation algorithms using different evaluation metrics measuring the accuracy, diversity, and novelty of the recommendations, and analyze the impact of the proposed parameters. We have found that our approach offers a competitive performance, outperforming content, collaborative, and hybrid baselines, and producing positive results when either content- or rating-based information is exploited. 相似文献
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个性化图书推荐主要是以用户特征和借阅行为为挖掘对象,通过获取用户的兴趣特征及隐含的需求模式,实现用户与图书相互关联的个性化图书推荐服务。本文通过挖掘用户的背景信息构建用户特征模型,然后在设计喜好值计算、用户相似度计算和内容相似度计算以及标签信息获取方法的基础上,研究多种不同的图书推荐方法,以挖掘用户的潜在信息需求。最后利用图书馆的真实数据设计面向高校图书馆的个性化图书推荐系统,同时以标准网络数据集通过实验验证来评估推荐方法的有效性。 相似文献
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【目的/意义】通过订阅记录获取用户兴趣爱好,并将协同过滤推荐方法应用于图书个性化推荐,为读者提供优质服务。【方法/过程】以协同过滤算法为基础,根据用户订阅记录,分别计算用户相似性和订阅图书相似性。针对传统协同过滤方法在计算热门订阅相似度时存在的缺陷,引入对订阅权重的惩罚机制,减轻了热门订阅会和很多订阅相似的可能性,并根据协同过滤方法,产生相应推荐结果。【结果/结论】运用公开可获取的数据集进行的算法验证表明,基于订阅记录的协同过滤算法推荐准确度较高,对提升用户图书借阅体验相关研究与实践有一定的参考价值。 相似文献
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Information filtering (IF) systems usually filter data items by correlating a set of terms representing the user’s interest (a user profile) with similar sets of terms representing the data items. Many techniques can be employed for constructing user profiles automatically, but they usually yield large sets of term. Various dimensionality-reduction techniques can be applied in order to reduce the number of terms in a user profile. We describe a new terms selection technique including a dimensionality-reduction mechanism which is based on the analysis of a trained artificial neural network (ANN) model. Its novel feature is the identification of an optimal set of terms that can classify correctly data items that are relevant to a user. The proposed technique was compared with the classical Rocchio algorithm. We found that when using all the distinct terms in the training set to train an ANN, the Rocchio algorithm outperforms the ANN based filtering system, but after applying the new dimensionality-reduction technique, leaving only an optimal set of terms, the improved ANN technique outperformed both the original ANN and the Rocchio algorithm. 相似文献
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One difficult problem in information retrieval (IR) is the proper interpretation of user queries. It is extremely hard for users to express their information needs in a specific yet exhaustive way. In an effort to alleviate this problem, two theoretical models have been proposed to utilize user characteristics maintained in the form of a user profile. Although the idea of integrating user profiles into an IR system is intuitively appealing, and the models seem viable, no research to date has established a foundation for the roles of user profiles in such a system. Aiming at the investigation of the roles of user profiles, therefore, this study first identifies and extends various query/profile interaction models to provide a ground upon which the investigation can be undertaken. From a continuum of models characterized on the basis of interaction types, metrics, and parameters, nearly 400 models are chosen to investigate the “model space.” New measures are developed based on the notion of user satisfaction/frustration. In addition, three different criteria are used to guide users in making judgments on the quality of retrieved items. Analysis of the data obtained from the experiments shows that, for a wide variety of criteria and metrics, there are always some query/profile interaction models that outperform the query alone model. In addition, preferable characteristics for different criteria are identified in terms of interaction types, parameters, and metrics. 相似文献